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leetcode题解64:最小路径和

描述

该题来自于力扣第64题

分析

力扣第62题的区别在于,是求最小和,还是用dp[i][j]表示达到i,j网格的最小和,那么转移方程为dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + grid[i][j],当然这是对i>0,j>0的情况,i==0j==0的情况,就更简单了,具体可以参考代码。

代码

python
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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]