【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

 

class Solution {
public:
    int minPathSum(vector<vector<int> > &grid) {
       
        int m=grid.size();
        int n=grid[0].size();
       
       /* int **dp=new int *[m];
        for(int i=0;i<m;i++)
        {
            dp[i]=new int[n];
        }
        */
       
        vector<vector<int>> dp(m,vector<int>(n));
       
        dp[0][0]=grid[0][0];
       
        for(int i=1;i<m;i++)
        {
            dp[i][0]=dp[i-1][0]+grid[i][0];
        }
       
        for(int j=1;j<n;j++)
        {
            dp[0][j]=dp[0][j-1]+grid[0][j];
        }
       
        for(int i=1;i<m;i++)
        {
            for(int j=1;j<n;j++)
            {
                dp[i][j]=grid[i][j]+min(dp[i-1][j],dp[i][j-1]);
            }
        }
       
        return dp[m-1][n-1];
       
    }
};