59 lines
1.7 KiB
Markdown
59 lines
1.7 KiB
Markdown
## \-\-- Day 9: All in a Single Night \-\--
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Every year, Santa manages to deliver all of his presents in a single
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night.
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This year, however, he has some [new
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locations]{title="Bonus points if you recognize all of the locations."}
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to visit; his elves have provided him the distances between every pair
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of locations. He can start and end at any two (different) locations he
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wants, but he must visit each location exactly once. What is the
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*shortest distance* he can travel to achieve this?
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For example, given the following distances:
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London to Dublin = 464
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London to Belfast = 518
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Dublin to Belfast = 141
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The possible routes are therefore:
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Dublin -> London -> Belfast = 982
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London -> Dublin -> Belfast = 605
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London -> Belfast -> Dublin = 659
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Dublin -> Belfast -> London = 659
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Belfast -> Dublin -> London = 605
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Belfast -> London -> Dublin = 982
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The shortest of these is `London -> Dublin -> Belfast = 605`, and so the
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answer is `605` in this example.
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What is the distance of the shortest route?
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Your puzzle answer was `117`.
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## \-\-- Part Two \-\-- {#part2}
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The next year, just to show off, Santa decides to take the route with
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the *longest distance* instead.
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He can still start and end at any two (different) locations he wants,
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and he still must visit each location exactly once.
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For example, given the distances above, the longest route would be `982`
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via (for example) `Dublin -> London -> Belfast`.
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What is the distance of the longest route?
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Your puzzle answer was `909`.
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Both parts of this puzzle are complete! They provide two gold stars:
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\*\*
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At this point, you should [return to your Advent calendar](/2015) and
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try another puzzle.
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If you still want to see it, you can [get your puzzle
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input](9/input).
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