Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.

Note: You can only move either down or right at any point in time.

 

思路：看到这道题想到两种方法，第一种是分支限界，不过时间复杂度比较高，估计会超时，另一种方法是动态规划，时间复杂度为O(m*n,代码如下：

1 class Solution { 2 public: 3     vector
     
      
       >  mi; 4     int minPathSum(vector
       
        
          > &grid) { 5         mi=grid; 6         for(int i=1;i