62. 不同路径(Medium)

Python示例

class Solution:
    def uniquePaths(self, m: int, n: int) -> int:
        dp = [[0] * n for _ in range(m)]
        # 先把边界条件计算好
        for i in range(n):
            dp[0][i] = 1
        for i in range(m):
            dp[i][0] = 1
        
        for i in range(1, m):
            for j in range(1, n):
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1]
        return dp[m - 1][n - 1]

Go示例

func uniquePaths(m int, n int) int {
    dp := make([][]int, m)
    for i:= 0; i < m; i++ {
        dp[i] = make([]int, n)
    }
    for i := 0; i < n; i++ {
       dp[0][i] = 1
    }
    for i := 0; i < m; i++ {
       dp[i][0] = 1
    }

    for i := 1; i < m; i++ {
        for j := 1; j < n; j++ {
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1]
        }
    }
    return dp[m - 1][n - 1]
}