64. 最小路径和（c++）

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

        for(int i = 1; i < n; i++){
            for(int j = 1; j < m; j++){
                dp[i][j] = min(dp[i-1][j],dp[i][j-1])+grid[i][j];
               // cout<