64. 最小路径和 @Python @Go

原题

https://leetcode.cn/problems/minimum-path-sum/

思路

动态规划

复杂度

时间：O(m * n)
空间：O(m * n)

Python代码

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

Go代码

func minPathSum(grid [][]int) int {
	m, n := len(grid), len(grid[0])
	dp := make([][]int, m)
	for i := 0; i < m; i++ {
		dp[i] = make([]int, n)
	}
	for i := 0; i < m; i++ {
		for j := 0; j < n; j++ {
			if i == 0 && j == 0 {
				dp[i][j] = grid[i][j]
			} else if i == 0 && j > 0 {
				dp[i][j] = dp[i][j-1] + grid[i][j]
			} else if j == 0 && i > 0 {
				dp[i][j] = dp[i-1][j] + grid[i][j]
			} else {
				dp[i][j] = min(dp[i-1][j], dp[i][j-1]) + grid[i][j]
			}
		}
	}
	return dp[m-1][n-1]
}