adventofcode/day01/problem

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<title>Day 1 - Advent of Code 2016</title>
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each, but the harder ones took 2-3 hours, and a few even longer than that. A
lot of effort went into building this thing - I hope you're enjoying playing it
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If you'd like to hang out, I'm @ericwastl on Twitter.
- Eric Wastl
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<header><div><h1 class="title-global"><a href="/">Advent of Code</a></h1><nav><ul><li><a href="/2016/about">[About]</a></li><li><a href="/2016/support">[AoC++]</a></li><li><a href="/2016/events">[Events]</a></li><li><a href="/2016/settings">[Settings]</a></li><li><a href="/2016/auth/logout">[Log Out]</a></li></ul></nav><div class="user">br0xen <span class="supporter">(AoC++)</span> <span class="star-count">1*</span></div></div><div><h1 class="title-event">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="title-event-wrap">λy.</span><a href="/2016">2016</a><span class="title-event-wrap"></span></h1><nav><ul><li><a href="/2016">[Calendar]</a></li><li><a href="/2016/leaderboard">[Leaderboard]</a></li><li><a href="/2016/stats">[Stats]</a></li><li><a href="/2016/sponsors">[Sponsors]</a></li></ul></nav></div></header>
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<article class="day-desc"><h2>--- Day 1: No Time for a Taxicab ---</h2><p>Santa's sleigh uses a <span title="An atomic clock is too inaccurate; he might end up in a wall!">very high-precision clock</span> to guide its movements, and the clock's oscillator is regulated by stars. Unfortunately, the stars have been stolen... by the Easter Bunny. To save Christmas, Santa needs you to retrieve all <em class="star">fifty stars</em> by December 25th.</p>
<p>Collect stars by solving puzzles. Two puzzles will be made available on each day in the advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants <em class="star">one star</em>. Good luck!</p>
<p>You're airdropped near <em>Easter Bunny Headquarters</em> in a city somewhere. "Near", unfortunately, is as close as you can get - the instructions on the Easter Bunny Recruiting Document the Elves intercepted start here, and nobody had time to work them out further.</p>
<p>The Document indicates that you should start at the given coordinates (where you just landed) and face North. Then, follow the provided sequence: either turn left (<code>L</code>) or right (<code>R</code>) 90 degrees, then walk forward the given number of blocks, ending at a new intersection.</p>
<p>There's no time to follow such ridiculous instructions on foot, though, so you take a moment and work out the destination. Given that you can only walk on the <a href="https://en.wikipedia.org/wiki/Taxicab_geometry">street grid of the city</a>, how far is the shortest path to the destination?</p>
<p>For example:</p>
<ul>
<li>Following <code>R2, L3</code> leaves you <code>2</code> blocks East and <code>3</code> blocks North, or <code>5</code> blocks away.</li>
<li><code>R2, R2, R2</code> leaves you <code>2</code> blocks due South of your starting position, which is <code>2</code> blocks away.</li>
<li><code>R5, L5, R5, R3</code> leaves you <code>12</code> blocks away.</li>
</ul>
<p><em>How many blocks away</em> is Easter Bunny HQ?</p>
</article>
<p>Your puzzle answer was <code>243</code>.</p><p class="day-success">The first half of this puzzle is complete! It provides one gold star: *</p>
<article class="day-desc"><h2>--- Part Two ---</h2><p>Then, you notice the instructions continue on the back of the Recruiting Document. Easter Bunny HQ is actually at the first location you visit twice.</p>
<p>For example, if your instructions are <code>R8, R4, R4, R8</code>, the first location you visit twice is <code>4</code> blocks away, due East.</p>
<p>How many blocks away is the <em>first location you visit twice</em>?</p>
</article>
<p>Although it hasn't changed, you can still <a href="1/input" target="_blank">get your puzzle input</a>.</p>
<form method="post" action="1/answer"><input type="hidden" name="level" value="2"/><p>Answer: <input type="text" name="answer" autocomplete="off"/> <input type="submit" value="[Submit]"/></p></form>
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