【leetcode】Minimum Path Sum

Minimum Path Sum

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.

 

动态规划即可，与Unique Path类似

 

 1 class Solution {

 2 public:

 3     int minPathSum(vector<vector<int> > &grid) {

 4        

 5         int m=grid.size();

 6         int n=grid[0].size();

 7        

 8        /* int **dp=new int *[m];

 9         for(int i=0;i<m;i++)

10         {

11             dp[i]=new int[n];

12         }

13         */

14        

15         vector<vector<int>> dp(m,vector<int>(n));

16        

17         dp[0][0]=grid[0][0];

18        

19         for(int i=1;i<m;i++)

20         {

21             dp[i][0]=dp[i-1][0]+grid[i][0];

22         }

23        

24         for(int j=1;j<n;j++)

25         {

26             dp[0][j]=dp[0][j-1]+grid[0][j];

27         }

28        

29         for(int i=1;i<m;i++)

30         {

31             for(int j=1;j<n;j++)

32             {

33                 dp[i][j]=grid[i][j]+min(dp[i-1][j],dp[i][j-1]);

34             }

35         }

36        

37         return dp[m-1][n-1];

38        

39     }

40 };