leetcode-120-三角形最小路径和

题目描述：

第一次提交：动态规划　　

class Solution:
    def minimumTotal(self, triangle: List[List[int]]) -> int:
        n = len(triangle)
        for i in range(n-2,-1,-1):
            for j in range(0,i+1):
                triangle[i][j] += min(triangle[i+1][j],triangle[i+1][j+1])
        return triangle[0][0]
            

另：不污染原数据

class Solution:
    def minimumTotal(self, triangle):
        l = len(triangle)
        if l == 0:
            return 0
        dp = triangle[-1]
        for i in range(l - 2, -1, -1):
            for j in range(len(triangle[i])):
                dp[j] = min(dp[j], dp[j + 1]) + triangle[i][j]
        return dp[0]