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Diffstat (limited to '2025/07/puzzle-2.py')
| -rwxr-xr-x | 2025/07/puzzle-2.py | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/2025/07/puzzle-2.py b/2025/07/puzzle-2.py new file mode 100755 index 0000000..3695889 --- /dev/null +++ b/2025/07/puzzle-2.py @@ -0,0 +1,31 @@ +#!/usr/bin/python3 + +import collections +import functools + + +Pos = collections.namedtuple('Pos', ['x', 'y']) + + +def main() -> None: + with open('input', 'r') as f: + grid = tuple(tuple(x.strip()) for x in f.readlines()) + + pos = Pos(grid[0].index('S'), 0) + print(npaths(grid, pos)) + + +@functools.cache +def npaths(grid: list[list[str]], pos: Pos) -> int: + if pos.y == len(grid): + return 1 + if grid[pos.y][pos.x] == '^': + return ( + npaths(grid, Pos(pos.x - 1, pos.y)) + + npaths(grid, Pos(pos.x + 1, pos.y)) + ) + return npaths(grid, Pos(pos.x, pos.y + 1)) + + +if __name__ == '__main__': + main() |