0064-minimum-path-sum.py

# time complexity: O(mn)
# space complexity: O(mn)
from typing import List


class Solution:
    def minPathSum(self, grid: List[List[int]]) -> int:
        m = len(grid)
        n = len(grid[0])
        for i in range(1, m):
            grid[i][0] += grid[i-1][0]
        for j in range(1, n):
            grid[0][j] += grid[0][j-1]
        for i in range(1, m):
            for j in range(1, n):
                grid[i][j] += min(grid[i-1][j], grid[i][j-1])
        return grid[m-1][n-1]


grid = [[1, 3, 1], [1, 5, 1], [4, 2, 1]]
print(Solution().minPathSum(grid))