leetcode [64] Minimum Path Sum

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

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