LeetCode_Minimum Path Sum

iven 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： grid[i][j] += min(grid[i-1][j], grid[i][j-1])

class Solution {

public:

    int minPathSum(vector<vector<int> > &grid) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        int m = grid.size();

        int n = grid[0].size();

        

        for(int i = 1; i< n ; i++)

             grid[0][i] += grid[0][i-1];

        for(int j = 1; j < m; j++)

            grid[j][0] += grid[j-1][0];

            

        for( int i = 1; i < m ; i++)

            for( int j = 1; j < n ; j++)

            {

                int temp = grid[i-1][j] < grid[i][j-1] ? grid[i-1][j] : grid[i][j-1];

                grid[i][j] +=temp;

            }

        

        return grid[m-1][n-1];

    }

};