题解 | #矩阵的最小路径和#

dp

#
# 
# @param matrix int整型二维数组 the matrix
# @return int整型
#
class Solution:
    def minPathSum(self , matrix ):
        # write code here
        m = len(matrix)
        if m == 0:
            return 0
        n = len(matrix[0])
        if n == 0:
            return 0
        dp = [[0 for _ in range(n)]for _ in range(m)]
        dp[0][0] = matrix[0][0]
        for i in range(1, m):
            dp[i][0] = matrix[i][0] + dp[i-1][0]
        for j in range(1, n):
            dp[0][j] = matrix[0][j] + dp[0][j-1]

        for i in range(1, m):
            for j in range(1, n):
                dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + matrix[i][j]

        return dp[m-1][n-1]