题解 | #矩阵的最小路径和#

class Solution:
    def minPathSum(self, matrix: List[List[int]]) -> int:
        if not matrix or not matrix[0]:
            return 0

        n, m = len(matrix), len(matrix[0])
        dp = [[0] * m for _ in range(n)]

        dp[0][0] = matrix[0][0]

        # 初始化第一行
        for j in range(1, m):
            dp[0][j] = dp[0][j - 1] + matrix[0][j]

        # 初始化第一列
        for i in range(1, n):
            dp[i][0] = dp[i - 1][0] + matrix[i][0]

        # 动态规划填表
        for i in range(1, n):
            for j in range(1, m):
                dp[i][j] = min(dp[i - 1][j], dp[i][j - 1]) + matrix[i][j]

        return dp[-1][-1]