advent-of-code-10.html

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  15 Oh, hello!  Funny seeing you here.
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  17 I appreciate your enthusiasm, but you aren't going to find much down here.
  18 There certainly aren't clues to any of the puzzles.  You do risk spoiling a few
  19 surprises for yourself, though.  Best to play the normal way and discover
  20 everything as it was intended, I think.  The best surprises don't even appear
  21 in the source until you unlock them for real.
  22
  23 Please be careful with automated requests; I'm not Google, and I can only take
  24 so much traffic.  Please be considerate so that everyone gets to play.
  25
  26 If you're curious about how Advent of Code works, it's running on some custom
  27 Perl code. Other than a few integrations (auth, analytics, ads, social media),
  28 I built the whole thing myself, including the design, animations, prose, and
  29 all of the puzzles.
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  31 The puzzles probably took the longest; the easiest ones were around 45 minutes
  32 each, but the harder ones took 2-3 hours, some even longer than that. A lot of
  33 effort went into building this thing - I hope you're enjoying playing it as
  34 much as I enjoyed making it for you!
  35
  36 If you'd like to hang out, I'm @ericwastl on Twitter.
  37
  38 - Eric Wastl
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  90 <body>
  91 <header><h1><a href="/">Advent of Code</a></h1><div class="user">Neil Smith <span class="star-count">26*</span></div><nav><ul><li><a href="/about">[About]</a></li><li><a href="/stats">[Stats]</a></li><li><a href="/leaderboard">[Leaderboard]</a></li><li><a href="/settings">[Settings]</a></li><li><a href="/auth/logout">[Log out]</a></li></ul></nav></header>
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 106 <article class="day-desc"><h2>--- Day 10: Elves Look, Elves Say ---</h2><p>Today, the Elves are playing a game called <a href="https://en.wikipedia.org/wiki/Look-and-say_sequence">look-and-say</a>.  They take turns making sequences by reading aloud the previous sequence and using that reading as the next sequence.  For example, <code>211</code> is read as "one two, two ones", which becomes <code>1221</code> (<code>1</code> <code>2</code>, <code>2</code> <code>1</code>s).</p>
 107 <p>Look-and-say sequences are generated iteratively, using the previous value as input for the next step.  For each step, take the previous value, and replace each run of digits (like <code>111</code>) with the number of digits (<code>3</code>) followed by the digit itself (<code>1</code>).</p>
 108 <p>For example:</p>
 109 <ul>
 110 <li><code>1</code> becomes <code>11</code> (<code>1</code> copy of digit <code>1</code>).</li>
 111 <li><code>11</code> becomes <code>21</code> (<code>2</code> copies of digit <code>1</code>).</li>
 112 <li><code>21</code> becomes <code>1211</code> (one <code>2</code> followed by one <code>1</code>).</li>
 113 <li><code>1211</code> becomes <code>111221</code> (one <code>1</code>, one <code>2</code>, and two <code>1</code>s).</li>
 114 <li><code>111221</code> becomes <code>312211</code> (three <code>1</code>s, two <code>2</code>s, and one <code>1</code>).</li>
 115 </ul>
 116 <p>Starting with the digits in your puzzle input, apply this process 40 times.  What is <em>the length of the result</em>?</p>
 117 </article>
 118 <p>Your puzzle answer was <code>329356</code>.</p><article class="day-desc"><h2>--- Part Two ---</h2><p>Neat, right? You might also enjoy hearing <a href="https://www.youtube.com/watch?v=ea7lJkEhytA">John Conway talking about this sequence</a> (that's Conway of <em>Conway's Game of Life</em> fame).</p>
 119 <p>Now, starting again with the digits in your puzzle input, apply this process <em title="Only because any longer started taking alarmingly long on my test hardware, and I wanted to avoid excluding people.">50</em> times.  What is <em>the length of the new result</em>?</p>
 120 </article>
 121 <p>Your puzzle answer was <code>4666278</code>.</p><p class="day-success">Both parts of this puzzle are complete! They provide two gold stars: **</p>
 122 <p>At this point, you should <a href="/">return to your advent calendar</a> and try another puzzle.</p>
 123 <p>Your puzzle input was <code class="puzzle-input">3113322113</code>.</p>
 124 <p>You can also <span class="share">[Share<span class="share-content">on
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 128 ></span>]</span>
 129  this puzzle.</p>
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