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.

//动态规划解决二维数组问题。

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