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| author | nsfisis <nsfisis@gmail.com> | 2022-08-31 23:30:53 +0900 |
|---|---|---|
| committer | nsfisis <nsfisis@gmail.com> | 2022-08-31 23:32:02 +0900 |
| commit | 5d5367ed00c22cc194b8a2411b2b4b828751003b (patch) | |
| tree | 02392cbb201091853c58ffccea81dbc8f9102854 /docs/posts/2022-04-09 | |
| parent | 8c071f04a749d2cf7ca7a23bff49d94738aa6b6d (diff) | |
| download | nsfisis.github.io-5d5367ed00c22cc194b8a2411b2b4b828751003b.tar.gz nsfisis.github.io-5d5367ed00c22cc194b8a2411b2b4b828751003b.tar.zst nsfisis.github.io-5d5367ed00c22cc194b8a2411b2b4b828751003b.zip | |
update hugo
Diffstat (limited to 'docs/posts/2022-04-09')
| -rw-r--r-- | docs/posts/2022-04-09/phperkaigi-2022-tokens/index.html | 388 |
1 files changed, 194 insertions, 194 deletions
diff --git a/docs/posts/2022-04-09/phperkaigi-2022-tokens/index.html b/docs/posts/2022-04-09/phperkaigi-2022-tokens/index.html index c74be74..4d4918e 100644 --- a/docs/posts/2022-04-09/phperkaigi-2022-tokens/index.html +++ b/docs/posts/2022-04-09/phperkaigi-2022-tokens/index.html @@ -15,7 +15,7 @@ <link href="https://blog.nsfisis.dev/custom.css" rel="stylesheet"> <link rel="icon" href="https://blog.nsfisis.dev/favicon.svg"> - <meta name="generator" content="Hugo 0.88.1" /> + <meta name="generator" content="Hugo 0.102.1" /> </head> @@ -50,76 +50,76 @@ <p>リポジトリはこちら: <a href="https://github.com/nsfisis/PHPerKaigi2022-tokens">https://github.com/nsfisis/PHPerKaigi2022-tokens</a></p> <h1 id="第1問-brainf_ckphp">第1問 brainf_ck.php</h1> <p>ソースコードはこちら。実行には PHP 8.1 以上が必要なので注意。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> - -<span style="color:#66d9ef">declare</span>(<span style="color:#a6e22e">strict_types</span><span style="color:#f92672">=</span><span style="color:#ae81ff">0</span><span style="color:#a6e22e">O1</span>); - -<span style="color:#66d9ef">namespace</span> <span style="color:#a6e22e">Dgcircus\PHPerKaigi\Y2022</span>; - -<span style="color:#e6db74">/** -</span><span style="color:#e6db74"> * @todo -</span><span style="color:#e6db74"> * Run this program to acquire a PHPer token. -</span><span style="color:#e6db74"> */</span> - -<span style="color:#a6e22e">https</span><span style="color:#f92672">://</span><span style="color:#a6e22e">creativecommons</span><span style="color:#f92672">.</span><span style="color:#a6e22e">org</span><span style="color:#f92672">/</span><span style="color:#a6e22e">publicdomain</span><span style="color:#f92672">/</span><span style="color:#a6e22e">zero</span><span style="color:#f92672">/</span><span style="color:#ae81ff">1.0</span><span style="color:#f92672">/</span> - -<span style="color:#a6e22e">\error_reporting</span>(<span style="color:#f92672">~+!</span><span style="color:#e6db74">'We are hiring!'</span>); - -$z <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($f) <span style="color:#f92672">=></span> (<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> $f(<span style="color:#a6e22e">fn</span>(<span style="color:#f92672">...</span>$xs) <span style="color:#f92672">=></span> $x($x)(<span style="color:#f92672">...</span>$xs)))(<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> $f(<span style="color:#a6e22e">fn</span>(<span style="color:#f92672">...</span>$xs) <span style="color:#f92672">=></span> $x($x)(<span style="color:#f92672">...</span>$xs))); -$id <span style="color:#f92672">=</span> <span style="color:#a6e22e">\spl_object_id</span>(<span style="color:#f92672">...</span>); -$put <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($c) <span style="color:#f92672">=></span> <span style="color:#a6e22e">\printf</span>(<span style="color:#e6db74">'%c'</span>, $c); -$mm <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($p, $n) <span style="color:#f92672">=></span> <span style="color:#66d9ef">new</span> <span style="color:#a6e22e">\ArrayObject</span>(<span style="color:#a6e22e">\array_fill</span>(<span style="color:#f92672">+!!</span>[], $n, $p)); - -$👉 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [<span style="color:#f92672">++</span>$mp, <span style="color:#f92672">++</span>$pc]; -$👈 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [<span style="color:#f92672">--</span>$mp, <span style="color:#f92672">++</span>$pc]; -$👍 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, <span style="color:#f92672">++</span>$m[$mp]]; -$👎 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, <span style="color:#f92672">--</span>$m[$mp]]; -$📝 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, $put($m[$mp])]; -$🤡 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($m[$mp]) { - <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">=></span> [$mp, $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($pc, $n) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($id($p[$pc])) { - $b <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">++</span>$pc, <span style="color:#f92672">++</span>$n), - $e <span style="color:#f92672">=></span> $n <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">?</span> <span style="color:#f92672">++</span>$pc <span style="color:#f92672">:</span> $loop(<span style="color:#f92672">++</span>$pc, <span style="color:#f92672">--</span>$n), - <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">++</span>$pc, $n), - })($pc, <span style="color:#f92672">-!</span>[])], - <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc], -}; -$🎪 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($m[$mp]) { - <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc], - <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> [$mp, $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($pc, $n) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($id($p[$pc])) { - $e <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">--</span>$pc, <span style="color:#f92672">++</span>$n), - $b <span style="color:#f92672">=></span> $n <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">?</span> $pc<span style="color:#f92672">+!</span>[] <span style="color:#f92672">:</span> $loop(<span style="color:#f92672">--</span>$pc, <span style="color:#f92672">--</span>$n), - <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">--</span>$pc, $n), - })($pc, <span style="color:#f92672">-!</span>[])], -}; -$🐘 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($p) <span style="color:#f92672">=></span> $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> - <span style="color:#a6e22e">isset</span>($p[$pc]) <span style="color:#f92672">&&</span> $loop($m, $p, $b, $e, <span style="color:#f92672">...</span>($p[$pc]($m, $p, $b, $e, $mp, $pc))) -)($mm(<span style="color:#f92672">+!!</span>[], <span style="color:#f92672">+</span>(<span style="color:#f92672">!</span>[]<span style="color:#f92672">.!</span>[])), $p, $id($🤡), $id($🎪), <span style="color:#f92672">+!!</span>[], <span style="color:#f92672">+!!</span>[]); - -$🐘([ - $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, - $🤡, - $👉, $👍, $👍, $👍, - $👉, $👍, $👍, $👍, $👍, $👍, - $👉, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, - $👉, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, - $👈, $👈, $👈, $👈, $👎, - $🎪, - $👉, $👍, $👍, $👍, $👍, $👍, $📝, - $👎, $👎, $📝, - $👉, $👎, $👎, $👎, $📝, - $👉, $👎, $👎, $👎, $📝, - $👎, $👎, $📝, - $👎, $📝, - $👈, $📝, - $👉, $👉, $👎, $👎, $📝, - $👍, $👍, $👍, $👍, $👍, $👍, $👍, $📝, - $👈, $👎, $👎, $👎, $👎, $📝, - $👈, $📝, - $👉, $👍, $👍, $📝, - $👉, $👎, $📝, - $👈, $📝, -]); -</code></pre></div><p>この問題は、単に適切なバージョンの PHP で動かせばトークンが得られる。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#66d9ef">declare</span>(<span style="color:#a6e22e">strict_types</span><span style="color:#f92672">=</span><span style="color:#ae81ff">0</span><span style="color:#a6e22e">O1</span>); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#66d9ef">namespace</span> <span style="color:#a6e22e">Dgcircus\PHPerKaigi\Y2022</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#e6db74">/** +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * @todo +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * Run this program to acquire a PHPer token. +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> */</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">https</span><span style="color:#f92672">://</span><span style="color:#a6e22e">creativecommons</span><span style="color:#f92672">.</span><span style="color:#a6e22e">org</span><span style="color:#f92672">/</span><span style="color:#a6e22e">publicdomain</span><span style="color:#f92672">/</span><span style="color:#a6e22e">zero</span><span style="color:#f92672">/</span><span style="color:#ae81ff">1.0</span><span style="color:#f92672">/</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">\error_reporting</span>(<span style="color:#f92672">~+!</span><span style="color:#e6db74">'We are hiring!'</span>); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$z <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($f) <span style="color:#f92672">=></span> (<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> $f(<span style="color:#a6e22e">fn</span>(<span style="color:#f92672">...</span>$xs) <span style="color:#f92672">=></span> $x($x)(<span style="color:#f92672">...</span>$xs)))(<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> $f(<span style="color:#a6e22e">fn</span>(<span style="color:#f92672">...</span>$xs) <span style="color:#f92672">=></span> $x($x)(<span style="color:#f92672">...</span>$xs))); +</span></span><span style="display:flex;"><span>$id <span style="color:#f92672">=</span> <span style="color:#a6e22e">\spl_object_id</span>(<span style="color:#f92672">...</span>); +</span></span><span style="display:flex;"><span>$put <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($c) <span style="color:#f92672">=></span> <span style="color:#a6e22e">\printf</span>(<span style="color:#e6db74">'%c'</span>, $c); +</span></span><span style="display:flex;"><span>$mm <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($p, $n) <span style="color:#f92672">=></span> <span style="color:#66d9ef">new</span> <span style="color:#a6e22e">\ArrayObject</span>(<span style="color:#a6e22e">\array_fill</span>(<span style="color:#f92672">+!!</span>[], $n, $p)); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$👉 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [<span style="color:#f92672">++</span>$mp, <span style="color:#f92672">++</span>$pc]; +</span></span><span style="display:flex;"><span>$👈 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [<span style="color:#f92672">--</span>$mp, <span style="color:#f92672">++</span>$pc]; +</span></span><span style="display:flex;"><span>$👍 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, <span style="color:#f92672">++</span>$m[$mp]]; +</span></span><span style="display:flex;"><span>$👎 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, <span style="color:#f92672">--</span>$m[$mp]]; +</span></span><span style="display:flex;"><span>$📝 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc, $put($m[$mp])]; +</span></span><span style="display:flex;"><span>$🤡 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($m[$mp]) { +</span></span><span style="display:flex;"><span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">=></span> [$mp, $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($pc, $n) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($id($p[$pc])) { +</span></span><span style="display:flex;"><span> $b <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">++</span>$pc, <span style="color:#f92672">++</span>$n), +</span></span><span style="display:flex;"><span> $e <span style="color:#f92672">=></span> $n <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">?</span> <span style="color:#f92672">++</span>$pc <span style="color:#f92672">:</span> $loop(<span style="color:#f92672">++</span>$pc, <span style="color:#f92672">--</span>$n), +</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">++</span>$pc, $n), +</span></span><span style="display:flex;"><span> })($pc, <span style="color:#f92672">-!</span>[])], +</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc], +</span></span><span style="display:flex;"><span>}; +</span></span><span style="display:flex;"><span>$🎪 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($m[$mp]) { +</span></span><span style="display:flex;"><span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">=></span> [$mp, <span style="color:#f92672">++</span>$pc], +</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> [$mp, $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($pc, $n) <span style="color:#f92672">=></span> <span style="color:#a6e22e">match</span> ($id($p[$pc])) { +</span></span><span style="display:flex;"><span> $e <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">--</span>$pc, <span style="color:#f92672">++</span>$n), +</span></span><span style="display:flex;"><span> $b <span style="color:#f92672">=></span> $n <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[] <span style="color:#f92672">?</span> $pc<span style="color:#f92672">+!</span>[] <span style="color:#f92672">:</span> $loop(<span style="color:#f92672">--</span>$pc, <span style="color:#f92672">--</span>$n), +</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">default</span> <span style="color:#f92672">=></span> $loop(<span style="color:#f92672">--</span>$pc, $n), +</span></span><span style="display:flex;"><span> })($pc, <span style="color:#f92672">-!</span>[])], +</span></span><span style="display:flex;"><span>}; +</span></span><span style="display:flex;"><span>$🐘 <span style="color:#f92672">=</span> <span style="color:#a6e22e">fn</span>($p) <span style="color:#f92672">=></span> $z(<span style="color:#a6e22e">fn</span>($loop) <span style="color:#f92672">=></span> <span style="color:#a6e22e">fn</span>($m, $p, $b, $e, $mp, $pc) <span style="color:#f92672">=></span> +</span></span><span style="display:flex;"><span> <span style="color:#a6e22e">isset</span>($p[$pc]) <span style="color:#f92672">&&</span> $loop($m, $p, $b, $e, <span style="color:#f92672">...</span>($p[$pc]($m, $p, $b, $e, $mp, $pc))) +</span></span><span style="display:flex;"><span>)($mm(<span style="color:#f92672">+!!</span>[], <span style="color:#f92672">+</span>(<span style="color:#f92672">!</span>[]<span style="color:#f92672">.!</span>[])), $p, $id($🤡), $id($🎪), <span style="color:#f92672">+!!</span>[], <span style="color:#f92672">+!!</span>[]); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$🐘([ +</span></span><span style="display:flex;"><span> $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, +</span></span><span style="display:flex;"><span> $🤡, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $👍, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $👍, $👍, $👍, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, $👍, +</span></span><span style="display:flex;"><span> $👈, $👈, $👈, $👈, $👎, +</span></span><span style="display:flex;"><span> $🎪, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $👍, $👍, $👍, $📝, +</span></span><span style="display:flex;"><span> $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👉, $👎, $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👉, $👎, $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👎, $📝, +</span></span><span style="display:flex;"><span> $👈, $📝, +</span></span><span style="display:flex;"><span> $👉, $👉, $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👍, $👍, $👍, $👍, $👍, $👍, $👍, $📝, +</span></span><span style="display:flex;"><span> $👈, $👎, $👎, $👎, $👎, $📝, +</span></span><span style="display:flex;"><span> $👈, $📝, +</span></span><span style="display:flex;"><span> $👉, $👍, $👍, $📝, +</span></span><span style="display:flex;"><span> $👉, $👎, $📝, +</span></span><span style="display:flex;"><span> $👈, $📝, +</span></span><span style="display:flex;"><span>]); +</span></span></code></pre></div><p>この問題は、単に適切なバージョンの PHP で動かせばトークンが得られる。</p> <h2 id="解説">解説</h2> <h3 id="絵文字">絵文字</h3> <p>まず目につくのは大量の絵文字だろう。 @@ -173,18 +173,18 @@ Brainf*ck とは、難解プログラミング言語のひとつであり、こ 今回は、PHP 8.1 から追加された、<code>0O</code> または <code>0o</code> から始まる八進数リテラルを使った。</p> <h3 id="url">URL</h3> <p>ソースコードのライセンスを示したこの部分だが、</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#a6e22e">https</span><span style="color:#f92672">://</span><span style="color:#a6e22e">creativecommons</span><span style="color:#f92672">.</span><span style="color:#a6e22e">org</span><span style="color:#f92672">/</span><span style="color:#a6e22e">publicdomain</span><span style="color:#f92672">/</span><span style="color:#a6e22e">zero</span><span style="color:#f92672">/</span><span style="color:#ae81ff">1.0</span><span style="color:#f92672">/</span> -</code></pre></div><p>完全に合法な PHP のコードである。 +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#a6e22e">https</span><span style="color:#f92672">://</span><span style="color:#a6e22e">creativecommons</span><span style="color:#f92672">.</span><span style="color:#a6e22e">org</span><span style="color:#f92672">/</span><span style="color:#a6e22e">publicdomain</span><span style="color:#f92672">/</span><span style="color:#a6e22e">zero</span><span style="color:#f92672">/</span><span style="color:#ae81ff">1.0</span><span style="color:#f92672">/</span> +</span></span></code></pre></div><p>完全に合法な PHP のコードである。 <code>https:</code> 部分はラベル、<code>//</code> 以降は行コメントになっている。</p> <h3 id="リテラルなしで数値を生成する">リテラルなしで数値を生成する</h3> <p>ソースコード中に、ほとんど数値リテラルが書かれていないことにお気づきだろうか。 PHP では、型変換を利用することで任意の整数を作り出すことができる。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[]); -<span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">1</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+!</span>[]); -<span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">2</span> <span style="color:#f92672">===</span> <span style="color:#f92672">!</span>[]<span style="color:#f92672">+!</span>[]); -<span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">3</span> <span style="color:#f92672">===</span> <span style="color:#f92672">!</span>[]<span style="color:#f92672">+!</span>[]<span style="color:#f92672">+!</span>[]); -<span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">10</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+</span>(<span style="color:#f92672">!</span>[]<span style="color:#f92672">.+!!</span>[])); -</code></pre></div><p><code>[]</code> に <code>!</code> を適用すると <code>true</code> が返ってくる。それに <code>+</code> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+!!</span>[]); +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">1</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+!</span>[]); +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">2</span> <span style="color:#f92672">===</span> <span style="color:#f92672">!</span>[]<span style="color:#f92672">+!</span>[]); +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">3</span> <span style="color:#f92672">===</span> <span style="color:#f92672">!</span>[]<span style="color:#f92672">+!</span>[]<span style="color:#f92672">+!</span>[]); +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">10</span> <span style="color:#f92672">===</span> <span style="color:#f92672">+</span>(<span style="color:#f92672">!</span>[]<span style="color:#f92672">.+!!</span>[])); +</span></span></code></pre></div><p><code>[]</code> に <code>!</code> を適用すると <code>true</code> が返ってくる。それに <code>+</code> を適用すると、<code>bool</code> から <code>int</code> ヘの型変換が走り、<code>1</code> が生成される。<code>10</code> はさらにトリッキーだ。まず <code>1</code> と <code>0</code> を作り、<code>.</code> で文字列として結合する (<code>'10'</code>)。これに <code>+</code> を適用すると、<code>string</code> から <code>int</code> @@ -204,57 +204,57 @@ PHP では、型変換を利用することで任意の整数を作り出すこ あまりに長い brainf*ck プログラムを書くとスタックオーバーフローする。</p> <h1 id="第2問-riddlephp">第2問 riddle.php</h1> <p>ソースコードはこちら。実行には PHP 8.0 以上が必要なので注意。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> - -<span style="color:#e6db74">/********************************************************* -</span><span style="color:#e6db74"> * This program displays a PHPer token. * -</span><span style="color:#e6db74"> * Guess 'N'. * -</span><span style="color:#e6db74"> * * -</span><span style="color:#e6db74"> * Hints: * -</span><span style="color:#e6db74"> * - N itself has no special meaning, e.g., 42, 8128, * -</span><span style="color:#e6db74"> * it is selected at random. * -</span><span style="color:#e6db74"> * - Each element of $token represents a single letter. * -</span><span style="color:#e6db74"> * - One letter consists of 5x5 cells. * -</span><span style="color:#e6db74"> * - Remember, the output is a complete PHPer token. * -</span><span style="color:#e6db74"> * * -</span><span style="color:#e6db74"> * License: * -</span><span style="color:#e6db74"> * https://creativecommons.org/publicdomain/zero/1.0/ * -</span><span style="color:#e6db74"> *********************************************************/</span> -<span style="color:#66d9ef">const</span> <span style="color:#66d9ef">N</span> <span style="color:#f92672">=</span> <span style="color:#ae81ff">0</span> <span style="color:#75715e">/* Change it to your answer. */</span>; -<span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672"><=</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672">&&</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672"><=</span> <span style="color:#ae81ff">0</span><span style="color:#a6e22e">b11111_11111_11111_11111_11111</span>); - -$token <span style="color:#f92672">=</span> [ - <span style="color:#ae81ff">0x14B499C</span>, - <span style="color:#ae81ff">0x0BE34CC</span>, <span style="color:#ae81ff">0x01C9C69</span>, - <span style="color:#ae81ff">0x0ECA069</span>, <span style="color:#ae81ff">0x01C2449</span>, <span style="color:#ae81ff">0x0FDB166</span>, <span style="color:#ae81ff">0x01C9C69</span>, - <span style="color:#ae81ff">0x01C1C66</span>, <span style="color:#ae81ff">0x0FC1C47</span>, <span style="color:#ae81ff">0x01C1C66</span>, - <span style="color:#ae81ff">0x10C5858</span>, <span style="color:#ae81ff">0x1E4E3B8</span>, <span style="color:#ae81ff">0x1A2F2F8</span>, -]; -<span style="color:#66d9ef">foreach</span> ($token <span style="color:#66d9ef">as</span> $x) { - $x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; - - $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); - $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); - $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); - <span style="color:#66d9ef">echo</span> <span style="color:#e6db74">"</span><span style="color:#e6db74">{</span>$x<span style="color:#e6db74">}</span><span style="color:#ae81ff">\n\n</span><span style="color:#e6db74">"</span>; -} -</code></pre></div><p>さて、この問題はさきほどのように単純に実行しただけでは、謎のブロックが表示されるだけでトークンは得られない。 +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#e6db74">/********************************************************* +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * This program displays a PHPer token. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * Guess 'N'. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * Hints: * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * - N itself has no special meaning, e.g., 42, 8128, * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * it is selected at random. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * - Each element of $token represents a single letter. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * - One letter consists of 5x5 cells. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * - Remember, the output is a complete PHPer token. * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * License: * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> * https://creativecommons.org/publicdomain/zero/1.0/ * +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"> *********************************************************/</span> +</span></span><span style="display:flex;"><span><span style="color:#66d9ef">const</span> <span style="color:#66d9ef">N</span> <span style="color:#f92672">=</span> <span style="color:#ae81ff">0</span> <span style="color:#75715e">/* Change it to your answer. */</span>; +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672"><=</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672">&&</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672"><=</span> <span style="color:#ae81ff">0</span><span style="color:#a6e22e">b11111_11111_11111_11111_11111</span>); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$token <span style="color:#f92672">=</span> [ +</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">0x14B499C</span>, +</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">0x0BE34CC</span>, <span style="color:#ae81ff">0x01C9C69</span>, +</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">0x0ECA069</span>, <span style="color:#ae81ff">0x01C2449</span>, <span style="color:#ae81ff">0x0FDB166</span>, <span style="color:#ae81ff">0x01C9C69</span>, +</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">0x01C1C66</span>, <span style="color:#ae81ff">0x0FC1C47</span>, <span style="color:#ae81ff">0x01C1C66</span>, +</span></span><span style="display:flex;"><span> <span style="color:#ae81ff">0x10C5858</span>, <span style="color:#ae81ff">0x1E4E3B8</span>, <span style="color:#ae81ff">0x1A2F2F8</span>, +</span></span><span style="display:flex;"><span>]; +</span></span><span style="display:flex;"><span><span style="color:#66d9ef">foreach</span> ($token <span style="color:#66d9ef">as</span> $x) { +</span></span><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); +</span></span><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); +</span></span><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); +</span></span><span style="display:flex;"><span> <span style="color:#66d9ef">echo</span> <span style="color:#e6db74">"</span><span style="color:#e6db74">{</span>$x<span style="color:#e6db74">}</span><span style="color:#ae81ff">\n\n</span><span style="color:#e6db74">"</span>; +</span></span><span style="display:flex;"><span>} +</span></span></code></pre></div><p>さて、この問題はさきほどのように単純に実行しただけでは、謎のブロックが表示されるだけでトークンは得られない。 トークンを得るためには、ソースコードを読み、定数 <code>N</code> を特定する必要がある。</p> <p>ここでは、私の想定解を解説する。</p> <h2 id="読解">読解</h2> <p>まずはソースコードを読んでいく。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php">$token <span style="color:#f92672">=</span> [ - <span style="color:#75715e">// 略 -</span><span style="color:#75715e"></span>]; -</code></pre></div><p>数値からなる <code>$token</code> があり、各要素をループしている。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"> $x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; -</code></pre></div><p>まずは排他的論理和 (xor) を取り、</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); -</code></pre></div><p>二進数に変換して、</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); -</code></pre></div><p>0 を空白に、1 を <code>#</code> にし、</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); -</code></pre></div><p>5文字ごとに区切ったあと、改行で結合している。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span>$token <span style="color:#f92672">=</span> [ +</span></span><span style="display:flex;"><span> <span style="color:#75715e">// 略 +</span></span></span><span style="display:flex;"><span><span style="color:#75715e"></span>]; +</span></span></code></pre></div><p>数値からなる <code>$token</code> があり、各要素をループしている。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; +</span></span></code></pre></div><p>まずは排他的論理和 (xor) を取り、</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); +</span></span></code></pre></div><p>二進数に変換して、</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); +</span></span></code></pre></div><p>0 を空白に、1 を <code>#</code> にし、</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span> $x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); +</span></span></code></pre></div><p>5文字ごとに区切ったあと、改行で結合している。</p> <h2 id="ヒント">ヒント</h2> <p>次に、ソースコードに書いてあるヒントを読んでいく。</p> <ul> @@ -268,76 +268,76 @@ $token <span style="color:#f92672">=</span> [ <h2 id="解く">解く</h2> <p>ここまでわかれば、あと一歩で解ける。すなわち、<code>0x14B499C</code> が <code>#</code> に変換されるような <code>N</code> を見つければよい。</p> <p><code>N</code> は高々</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672"><=</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672">&&</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672"><=</span> <span style="color:#ae81ff">0</span><span style="color:#a6e22e">b11111_11111_11111_11111_11111</span>); -</code></pre></div><p>なのでブルートフォースしてもよいが、ここではブルートフォースしない方法を紹介する。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> - -$x <span style="color:#f92672">=</span> <span style="color:#ae81ff">0x14B499C</span>; - -$x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; - -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); - -<span style="color:#a6e22e">assert</span>($x <span style="color:#f92672">===</span> - <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">" # # "</span>); -</code></pre></div><p>この一連の変換に対する逆変換を考えると、次のようになる。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> - -$x <span style="color:#f92672">=</span> - <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> - <span style="color:#e6db74">" # # "</span>; - -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">''</span>, <span style="color:#a6e22e">explode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, $x)); -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); -$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">bindec</span>($x); - -$n <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#ae81ff">0x14B499C</span>; - -<span style="color:#66d9ef">echo</span> <span style="color:#e6db74">"N = </span><span style="color:#e6db74">$n\n</span><span style="color:#e6db74">"</span>; -</code></pre></div><p>これを実行すると、<code>N</code> が得られる。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>(<span style="color:#ae81ff">0</span> <span style="color:#f92672"><=</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672">&&</span> <span style="color:#a6e22e">N</span> <span style="color:#f92672"><=</span> <span style="color:#ae81ff">0</span><span style="color:#a6e22e">b11111_11111_11111_11111_11111</span>); +</span></span></code></pre></div><p>なのでブルートフォースしてもよいが、ここではブルートフォースしない方法を紹介する。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#ae81ff">0x14B499C</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#a6e22e">N</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'%025b'</span>, $x); +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>($x, <span style="color:#a6e22e">length</span><span style="color:#f92672">:</span> <span style="color:#ae81ff">5</span>)); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">assert</span>($x <span style="color:#f92672">===</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # "</span>); +</span></span></code></pre></div><p>この一連の変換に対する逆変換を考えると、次のようになる。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # </span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">"#####</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span> <span style="color:#f92672">.</span> +</span></span><span style="display:flex;"><span> <span style="color:#e6db74">" # # "</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">''</span>, <span style="color:#a6e22e">explode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, $x)); +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_replace</span>(<span style="color:#a6e22e">search</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">' '</span>, <span style="color:#e6db74">'#'</span>], <span style="color:#a6e22e">replace</span><span style="color:#f92672">:</span> [<span style="color:#e6db74">'0'</span>, <span style="color:#e6db74">'1'</span>], <span style="color:#a6e22e">subject</span><span style="color:#f92672">:</span> $x); +</span></span><span style="display:flex;"><span>$x <span style="color:#f92672">=</span> <span style="color:#a6e22e">bindec</span>($x); +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span>$n <span style="color:#f92672">=</span> $x <span style="color:#f92672">^</span> <span style="color:#ae81ff">0x14B499C</span>; +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#66d9ef">echo</span> <span style="color:#e6db74">"N = </span><span style="color:#e6db74">$n\n</span><span style="color:#e6db74">"</span>; +</span></span></code></pre></div><p>これを実行すると、<code>N</code> が得られる。</p> <h1 id="第3問-toquinephp">第3問 toquine.php</h1> <p>ソースコードはこちら。</p> -<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4"><code class="language-php" data-lang="php"><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> - -<span style="color:#75715e">// License: https://creativecommons.org/publicdomain/zero/1.0/ -</span><span style="color:#75715e">// This is a quine-like program to generate a PHPer token. -</span><span style="color:#75715e">// Execute it like this: php toquine.php | php | php | php | ... -</span><span style="color:#75715e"></span> -$s <span style="color:#f92672">=</span> <span style="color:#e6db74"><<<'</span><span style="color:#e6db74">Q</span><span style="color:#e6db74">' -</span><span style="color:#e6db74"><?cuc -</span><span style="color:#e6db74">// Yvprafr: uggcf://perngvirpbzzbaf.bet/choyvpqbznva/mreb/1.0/ -</span><span style="color:#e6db74">// Guvf vf n dhvar-yvxr cebtenz gb trarengr n CUCre gbxra. -</span><span style="color:#e6db74">// Rkrphgr vg yvxr guvf: cuc gbdhvar.cuc | cuc | cuc | cuc | ... -</span><span style="color:#e6db74">%f$f = %f; -</span><span style="color:#e6db74">$f = fge_ebg13($f); $kf = [ -</span><span style="color:#e6db74">%f, -</span><span style="color:#e6db74">]; -</span><span style="color:#e6db74">$g = ahyy.snyfr; sbe ($v = 0; $v <= vagqvi(__YVAR__-035,6); ++$v) vs (!vffrg($kf[$v])) oernx; ryfr -</span><span style="color:#e6db74">$g .= vzcybqr("\a", fge_fcyvg(fge_ercynpr(['0','1'], [' ','##'], fcevags(pue(37) . '025o', $kf[$v])), 012)) . "\a\a"; -</span><span style="color:#e6db74">$jf = neenl_znc(sa($j) => vzcybqr(', ', $j), neenl_puhax(neenl_znc(sa($k) => fcevags('0k' . pue(37) . '07K', $k), $kf), 10)); -</span><span style="color:#e6db74">cevags($f, $g, fge_ebg13("<<<'Q'\a{$f}\aQ"), vzcybqr(",\a", $jf)); -</span><span style="color:#e6db74"></span><span style="color:#e6db74">Q</span>; -$s <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_rot13</span>($s); $xs <span style="color:#f92672">=</span> [ -<span style="color:#ae81ff">0x0AFABEA</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F2109F</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x0002800</span>, <span style="color:#ae81ff">0x1F2109F</span>, <span style="color:#ae81ff">0x0117041</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1F295B7</span>, -<span style="color:#ae81ff">0x010FC21</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1151151</span>, <span style="color:#ae81ff">0x010FC21</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F295B7</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F295B7</span>, <span style="color:#ae81ff">0x1F8C63F</span>, -<span style="color:#ae81ff">0x1F8C631</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x17AD6BD</span>, <span style="color:#ae81ff">0x17AD6BD</span>, <span style="color:#ae81ff">0x1F8C63F</span>, <span style="color:#ae81ff">0x1F295B7</span>, -]; -$t <span style="color:#f92672">=</span> <span style="color:#66d9ef">null</span><span style="color:#f92672">.</span><span style="color:#66d9ef">false</span>; <span style="color:#66d9ef">for</span> ($i <span style="color:#f92672">=</span> <span style="color:#ae81ff">0</span>; $i <span style="color:#f92672"><=</span> <span style="color:#a6e22e">intdiv</span>(<span style="color:#66d9ef">__LINE__</span><span style="color:#f92672">-</span><span style="color:#ae81ff">035</span>,<span style="color:#ae81ff">6</span>); <span style="color:#f92672">++</span>$i) <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span><span style="color:#a6e22e">isset</span>($xs[$i])) <span style="color:#66d9ef">break</span>; <span style="color:#66d9ef">else</span> -$t <span style="color:#f92672">.=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>(<span style="color:#a6e22e">str_replace</span>([<span style="color:#e6db74">'0'</span>,<span style="color:#e6db74">'1'</span>], [<span style="color:#e6db74">' '</span>,<span style="color:#e6db74">'##'</span>], <span style="color:#a6e22e">sprintf</span>(<span style="color:#a6e22e">chr</span>(<span style="color:#ae81ff">37</span>) <span style="color:#f92672">.</span> <span style="color:#e6db74">'025b'</span>, $xs[$i])), <span style="color:#ae81ff">012</span>)) <span style="color:#f92672">.</span> <span style="color:#e6db74">"</span><span style="color:#ae81ff">\n\n</span><span style="color:#e6db74">"</span>; -$ws <span style="color:#f92672">=</span> <span style="color:#a6e22e">array_map</span>(<span style="color:#a6e22e">fn</span>($w) <span style="color:#f92672">=></span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">', '</span>, $w), <span style="color:#a6e22e">array_chunk</span>(<span style="color:#a6e22e">array_map</span>(<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'0x'</span> <span style="color:#f92672">.</span> <span style="color:#a6e22e">chr</span>(<span style="color:#ae81ff">37</span>) <span style="color:#f92672">.</span> <span style="color:#e6db74">'07X'</span>, $x), $xs), <span style="color:#ae81ff">10</span>)); -<span style="color:#a6e22e">printf</span>($s, $t, <span style="color:#a6e22e">str_rot13</span>(<span style="color:#e6db74">"<<<'D'</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">{</span>$s<span style="color:#e6db74">}</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">D"</span>), <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">",</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, $ws)); -</code></pre></div><p>コメントにもあるとおり、次のようにして実行すれば答えがでてくる。</p> -<pre tabindex="0"><code class="language-shell-session" data-lang="shell-session">$ php toquine.php | php | php | php | ... -</code></pre><p>実際にはもう少しパイプで繋げなければならない。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-php" data-lang="php"><span style="display:flex;"><span><span style="color:#f92672"><?</span><span style="color:#a6e22e">php</span> +</span></span><span style="display:flex;"><span> +</span></span><span style="display:flex;"><span><span style="color:#75715e">// License: https://creativecommons.org/publicdomain/zero/1.0/ +</span></span></span><span style="display:flex;"><span><span style="color:#75715e">// This is a quine-like program to generate a PHPer token. +</span></span></span><span style="display:flex;"><span><span style="color:#75715e">// Execute it like this: php toquine.php | php | php | php | ... +</span></span></span><span style="display:flex;"><span><span style="color:#75715e"></span> +</span></span><span style="display:flex;"><span>$s <span style="color:#f92672">=</span> <span style="color:#e6db74"><<<'</span><span style="color:#e6db74">Q</span><span style="color:#e6db74">' +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"><?cuc +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">// Yvprafr: uggcf://perngvirpbzzbaf.bet/choyvpqbznva/mreb/1.0/ +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">// Guvf vf n dhvar-yvxr cebtenz gb trarengr n CUCre gbxra. +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">// Rkrphgr vg yvxr guvf: cuc gbdhvar.cuc | cuc | cuc | cuc | ... +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">%f$f = %f; +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">$f = fge_ebg13($f); $kf = [ +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">%f, +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">]; +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">$g = ahyy.snyfr; sbe ($v = 0; $v <= vagqvi(__YVAR__-035,6); ++$v) vs (!vffrg($kf[$v])) oernx; ryfr +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">$g .= vzcybqr("\a", fge_fcyvg(fge_ercynpr(['0','1'], [' ','##'], fcevags(pue(37) . '025o', $kf[$v])), 012)) . "\a\a"; +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">$jf = neenl_znc(sa($j) => vzcybqr(', ', $j), neenl_puhax(neenl_znc(sa($k) => fcevags('0k' . pue(37) . '07K', $k), $kf), 10)); +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74">cevags($f, $g, fge_ebg13("<<<'Q'\a{$f}\aQ"), vzcybqr(",\a", $jf)); +</span></span></span><span style="display:flex;"><span><span style="color:#e6db74"></span><span style="color:#e6db74">Q</span>; +</span></span><span style="display:flex;"><span>$s <span style="color:#f92672">=</span> <span style="color:#a6e22e">str_rot13</span>($s); $xs <span style="color:#f92672">=</span> [ +</span></span><span style="display:flex;"><span><span style="color:#ae81ff">0x0AFABEA</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F2109F</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x0002800</span>, <span style="color:#ae81ff">0x1F2109F</span>, <span style="color:#ae81ff">0x0117041</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1F295B7</span>, +</span></span><span style="display:flex;"><span><span style="color:#ae81ff">0x010FC21</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1151151</span>, <span style="color:#ae81ff">0x010FC21</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F295B7</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x1F294A7</span>, <span style="color:#ae81ff">0x1F295B7</span>, <span style="color:#ae81ff">0x1F8C63F</span>, +</span></span><span style="display:flex;"><span><span style="color:#ae81ff">0x1F8C631</span>, <span style="color:#ae81ff">0x1FAD6B5</span>, <span style="color:#ae81ff">0x17AD6BD</span>, <span style="color:#ae81ff">0x17AD6BD</span>, <span style="color:#ae81ff">0x1F8C63F</span>, <span style="color:#ae81ff">0x1F295B7</span>, +</span></span><span style="display:flex;"><span>]; +</span></span><span style="display:flex;"><span>$t <span style="color:#f92672">=</span> <span style="color:#66d9ef">null</span><span style="color:#f92672">.</span><span style="color:#66d9ef">false</span>; <span style="color:#66d9ef">for</span> ($i <span style="color:#f92672">=</span> <span style="color:#ae81ff">0</span>; $i <span style="color:#f92672"><=</span> <span style="color:#a6e22e">intdiv</span>(<span style="color:#66d9ef">__LINE__</span><span style="color:#f92672">-</span><span style="color:#ae81ff">035</span>,<span style="color:#ae81ff">6</span>); <span style="color:#f92672">++</span>$i) <span style="color:#66d9ef">if</span> (<span style="color:#f92672">!</span><span style="color:#a6e22e">isset</span>($xs[$i])) <span style="color:#66d9ef">break</span>; <span style="color:#66d9ef">else</span> +</span></span><span style="display:flex;"><span>$t <span style="color:#f92672">.=</span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">"</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, <span style="color:#a6e22e">str_split</span>(<span style="color:#a6e22e">str_replace</span>([<span style="color:#e6db74">'0'</span>,<span style="color:#e6db74">'1'</span>], [<span style="color:#e6db74">' '</span>,<span style="color:#e6db74">'##'</span>], <span style="color:#a6e22e">sprintf</span>(<span style="color:#a6e22e">chr</span>(<span style="color:#ae81ff">37</span>) <span style="color:#f92672">.</span> <span style="color:#e6db74">'025b'</span>, $xs[$i])), <span style="color:#ae81ff">012</span>)) <span style="color:#f92672">.</span> <span style="color:#e6db74">"</span><span style="color:#ae81ff">\n\n</span><span style="color:#e6db74">"</span>; +</span></span><span style="display:flex;"><span>$ws <span style="color:#f92672">=</span> <span style="color:#a6e22e">array_map</span>(<span style="color:#a6e22e">fn</span>($w) <span style="color:#f92672">=></span> <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">', '</span>, $w), <span style="color:#a6e22e">array_chunk</span>(<span style="color:#a6e22e">array_map</span>(<span style="color:#a6e22e">fn</span>($x) <span style="color:#f92672">=></span> <span style="color:#a6e22e">sprintf</span>(<span style="color:#e6db74">'0x'</span> <span style="color:#f92672">.</span> <span style="color:#a6e22e">chr</span>(<span style="color:#ae81ff">37</span>) <span style="color:#f92672">.</span> <span style="color:#e6db74">'07X'</span>, $x), $xs), <span style="color:#ae81ff">10</span>)); +</span></span><span style="display:flex;"><span><span style="color:#a6e22e">printf</span>($s, $t, <span style="color:#a6e22e">str_rot13</span>(<span style="color:#e6db74">"<<<'D'</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">{</span>$s<span style="color:#e6db74">}</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">D"</span>), <span style="color:#a6e22e">implode</span>(<span style="color:#e6db74">",</span><span style="color:#ae81ff">\n</span><span style="color:#e6db74">"</span>, $ws)); +</span></span></code></pre></div><p>コメントにもあるとおり、次のようにして実行すれば答えがでてくる。</p> +<div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-shell-session" data-lang="shell-session"><span style="display:flex;"><span>$ php toquine.php | php | php | php | ... +</span></span></code></pre></div><p>実際にはもう少しパイプで繋げなければならない。</p> <h2 id="解説-1">解説</h2> <h3 id="プログラム全体-1">プログラム全体</h3> <p>コメントにもあるとおり、これは quine (風) のプログラムになっている。 |