mirror of
https://github.com/Threnklyn/advent-of-code-go.git
synced 2026-05-19 03:23:27 +02:00
alexchao26
77 lines
1.9 KiB
Python
77 lines
1.9 KiB
Python
#!/usr/bin/env python3
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from typing import List
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example = """7 6 4 2 1
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1 2 7 8 9
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9 7 6 2 1
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1 3 2 4 5
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8 6 4 4 1
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1 3 6 7 9"""
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def part1(grid: List[List[int]]) -> int:
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valid_levels = 0
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for level in grid:
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if test_level(level):
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valid_levels += 1
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return valid_levels
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def part2(grid: List[List[int]]) -> int:
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# tolerate one bad level...
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valid_levels: int = 0
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for level in grid:
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for i in range(len(level)):
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newLevel: List[int] = level.copy()
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newLevel.pop(i) # removes i-th element?, how convenient..
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if test_level(newLevel):
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valid_levels += 1
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break
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return valid_levels
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def test_level(level: List[int]) -> bool:
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is_increasing = level[1] > level[0]
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is_valid = True
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# The levels are either all increasing or all decreasing.
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# Any two adjacent levels differ by at least one and at most three.
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for i in range(1, len(level)):
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if is_increasing and level[i] <= level[i - 1]:
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return False
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elif not is_increasing and level[i] >= level[i - 1]:
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return False
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diff = abs(level[i] - level[i - 1])
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if diff < 1 or diff > 3:
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return False
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return is_valid
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def convert_input(input: str) -> List[List[int]]:
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grid: List[List[int]] = []
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for level in input.splitlines():
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grid.append([int(part) for part in level.split(" ")])
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# converted_level: List[int] = []
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# this syntax is going to take getting used to...
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# for part in level.split(" "):
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# converted_level.append(int(part))
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# grid.append(converted_level)
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return grid
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example_grid = convert_input(example)
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print("example part1:", part1(example_grid), "want", 2)
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input = open("input.txt", "r").read()
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grid = convert_input(input)
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print("part1:", part1(grid), "want", 585)
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print("example part2:", part2(example_grid), "want", 4)
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print("part2:", part2(grid), "want", 626)
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