[64] 最小路径和

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