mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-27 23:11:09 +00:00
bc8df6de31
* [pre-commit.ci] pre-commit autoupdate updates: - [github.com/astral-sh/ruff-pre-commit: v0.2.2 → v0.3.2](https://github.com/astral-sh/ruff-pre-commit/compare/v0.2.2...v0.3.2) - [github.com/pre-commit/mirrors-mypy: v1.8.0 → v1.9.0](https://github.com/pre-commit/mirrors-mypy/compare/v1.8.0...v1.9.0) * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
49 lines
1.5 KiB
Python
49 lines
1.5 KiB
Python
"""
|
|
Problem 81: https://projecteuler.net/problem=81
|
|
In the 5 by 5 matrix below, the minimal path sum from the top left to the bottom right,
|
|
by only moving to the right and down, is indicated in bold red and is equal to 2427.
|
|
|
|
[131] 673 234 103 18
|
|
[201] [96] [342] 965 150
|
|
630 803 [746] [422] 111
|
|
537 699 497 [121] 956
|
|
805 732 524 [37] [331]
|
|
|
|
Find the minimal path sum from the top left to the bottom right by only moving right
|
|
and down in matrix.txt (https://projecteuler.net/project/resources/p081_matrix.txt),
|
|
a 31K text file containing an 80 by 80 matrix.
|
|
"""
|
|
|
|
import os
|
|
|
|
|
|
def solution(filename: str = "matrix.txt") -> int:
|
|
"""
|
|
Returns the minimal path sum from the top left to the bottom right of the matrix.
|
|
>>> solution()
|
|
427337
|
|
"""
|
|
with open(os.path.join(os.path.dirname(__file__), filename)) as in_file:
|
|
data = in_file.read()
|
|
|
|
grid = [[int(cell) for cell in row.split(",")] for row in data.strip().splitlines()]
|
|
dp = [[0 for cell in row] for row in grid]
|
|
n = len(grid[0])
|
|
|
|
dp = [[0 for i in range(n)] for j in range(n)]
|
|
dp[0][0] = grid[0][0]
|
|
for i in range(1, n):
|
|
dp[0][i] = grid[0][i] + dp[0][i - 1]
|
|
for i in range(1, n):
|
|
dp[i][0] = grid[i][0] + dp[i - 1][0]
|
|
|
|
for i in range(1, n):
|
|
for j in range(1, n):
|
|
dp[i][j] = grid[i][j] + min(dp[i - 1][j], dp[i][j - 1])
|
|
|
|
return dp[-1][-1]
|
|
|
|
|
|
if __name__ == "__main__":
|
|
print(f"{solution() = }")
|