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comparison 2017/day16/problem @ 34:049fb8e56025
Add problem statements and inputs
| author | Jordi Gutiérrez Hermoso <jordigh@octave.org> |
|---|---|
| date | Tue, 09 Jan 2018 21:51:44 -0500 |
| parents | |
| children |
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| 33:bc652fa0a645 | 34:049fb8e56025 |
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| 1 --- Day 16: Permutation Promenade --- | |
| 2 | |
| 3 You come upon a very unusual sight; a group of programs here appear to | |
| 4 be dancing. | |
| 5 | |
| 6 There are sixteen programs in total, named a through p. They start by | |
| 7 standing in a line: a stands in position 0, b stands in position 1, | |
| 8 and so on until p, which stands in position 15. | |
| 9 | |
| 10 The programs' dance consists of a sequence of dance moves: | |
| 11 | |
| 12 Spin, written sX, makes X programs move from the end to the front, | |
| 13 but maintain their order otherwise. (For example, s3 on abcde | |
| 14 produces cdeab). | |
| 15 | |
| 16 Exchange, written xA/B, makes the programs at positions A and B | |
| 17 swap places. | |
| 18 | |
| 19 Partner, written pA/B, makes the programs named A and B swap | |
| 20 places. | |
| 21 | |
| 22 | |
| 23 For example, with only five programs standing in a line (abcde), they | |
| 24 could do the following dance: | |
| 25 | |
| 26 s1, a spin of size 1: eabcd. | |
| 27 | |
| 28 x3/4, swapping the last two programs: eabdc. | |
| 29 | |
| 30 pe/b, swapping programs e and b: baedc. | |
| 31 | |
| 32 After finishing their dance, the programs end up in order baedc. | |
| 33 | |
| 34 You watch the dance for a while and record their dance moves (your | |
| 35 puzzle input). In what order are the programs standing after their | |
| 36 dance? | |
| 37 | |
| 38 Your puzzle answer was bkgcdefiholnpmja. | |
| 39 | |
| 40 --- Part Two --- | |
| 41 | |
| 42 Now that you're starting to get a feel for the dance moves, you turn | |
| 43 your attention to the dance as a whole. | |
| 44 | |
| 45 Keeping the positions they ended up in from their previous dance, the | |
| 46 programs perform it again and again: including the first dance, a | |
| 47 total of one billion (1000000000) times. | |
| 48 | |
| 49 In the example above, their second dance would begin with the order | |
| 50 baedc, and use the same dance moves: | |
| 51 | |
| 52 s1, a spin of size 1: cbaed. | |
| 53 | |
| 54 x3/4, swapping the last two programs: cbade. | |
| 55 | |
| 56 pe/b, swapping programs e and b: ceadb. | |
| 57 | |
| 58 In what order are the programs standing after their billion dances? | |
| 59 | |
| 60 Your puzzle answer was knmdfoijcbpghlea. | |
| 61 | |
| 62 Both parts of this puzzle are complete! They provide two gold stars: ** |