LeetCode-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.

对mxn的格子扫一遍，每个格子的值等于上方和左方格子值中较小的

class Solution {
public:
    int minPathSum(vector<vector<int> > &grid) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        if(grid.size()==0||grid[0].size()==0)return 0;
        for(int i=1;i<grid.size();i++){
            grid[i][0]+=grid[i-1][0];
        }
        for(int j=1;j<grid[0].size();j++){
            grid[0][j]+=grid[0][j-1];
        }
        for(int i=1;i<grid.size();i++){
            for(int j=1;j<grid[i].size();j++){
                grid[i][j]=min(grid[i-1][j],grid[i][j-1])+grid[i][j];
            }
        }
        return grid[grid.size()-1][grid[0].size()-1];
    }
};