Anders Ytterström
95c244102f
Yet again I got stuck in the common AOC trap: The example input worked, but not the actual input. 2 things got me stuck. > The size of a basin is the number of locations within the basin, including the low point. The example above has four basins. 1. I missed the obvious part to only check the low points. 2. Based on the example, I asumed that the adjacent locations would increase by one to count. This is wrong: What matters is that their height is a larger value. Way too long time for a simple problem. Never read puzzles sloppy.
70 lines
1.9 KiB
Python
70 lines
1.9 KiB
Python
from solutions import BaseSolution
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from typing import List, Tuple
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class Solution(BaseSolution):
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input_file = "09.txt"
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def __str__(self):
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return "Day 9: Smoke Basin"
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def parse_input(self, data):
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return [[int(c) for c in r] for r in data.split()]
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def solve(self, puzzle_input):
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lp = self._lowpoints(puzzle_input)
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return sum(lpv[1] + 1 for lpv in lp)
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def solve_again(self, puzzle_input):
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offsets = (-1, 0), (0, 1), (1, 0), (0, -1)
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my = len(puzzle_input)
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mx = len(puzzle_input[0])
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basins = []
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def basin(y, x, value, seen=set()):
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if value < 9:
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seen.add((value, (y, x)))
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for oy, ox in offsets:
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sy = y + oy
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sx = x + ox
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if any((sy < 0, sx < 0, sy >= my, sx >= mx)):
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continue
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s = puzzle_input[sy][sx]
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if s > value:
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seen = basin(sy, sx, s, seen)
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return seen
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for lp, value in self._lowpoints(puzzle_input):
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y, x = lp
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basins.append(len(basin(y, x, value, set())))
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p1, p2, p3, *_ = sorted(basins, reverse=True)
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return p1 * p2 * p3
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def _lowpoints(self, puzzle_input):
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lp = []
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lpi = len(puzzle_input)
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for v, row in enumerate(puzzle_input):
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lr = len(row)
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for i in range(lr):
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x = row[i]
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s1 = row[i - 1] if i > 0 else 11
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s2 = row[i + 1] if i < lr - 1 else 11
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s3 = puzzle_input[v - 1][i] if v > 0 else 11
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s4 = puzzle_input[v + 1][i] if v < lpi - 1 else 11
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if all(x < s for s in [s1, s2, s3, s4]):
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lp.append(((v, i), x))
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return lp
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if __name__ == "__main__":
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solution = Solution()
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solution.show_results()
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"""
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2199943210
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3987894921
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9856789892
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8767896789
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9899965678
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"""
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