day15: add python solution

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Xiretza 2020-12-15 11:27:54 +01:00
parent 96ce02443c
commit f36f28dac1
Signed by: xiretza
GPG key ID: 17B78226F7139993
4 changed files with 31 additions and 0 deletions

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@ -19,5 +19,6 @@ https://adventofcode.com/2020/
|11 | `**` | | |
|13 | | `**` | |
|14 | | `**` | |
|15 | `**` | | |
`test.sh` can be used to run all solutions and automatically compares them to (my) puzzle inputs and the expected outputs.

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data/day15.expected Normal file
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496
883

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2,0,1,7,4,14,18

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day15/day15.py Normal file
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#!/usr/bin/env python
import sys
def run_game(init, iterations):
last_seen = {}
previous = None
for i, n in enumerate(init):
if previous is not None:
last_seen[previous] = i-1
previous = n
for i in range(i+1, iterations):
if previous in last_seen:
x = i - last_seen[previous] - 1
else:
x = 0
last_seen[previous] = i-1
previous = x
return previous
if __name__ == '__main__':
init = [int(n) for n in sys.stdin.read().split(',')]
print(run_game(init, 2020))
print(run_game(init, 30000000))