minimum-path-sum-动态规划

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.

找出从左上到右下路径数字之和最小

记得先处理最上和左边一行

class Solution {
public:
    int minPathSum(vector<vector<int> > &grid) {
        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]);
            }
        }
        return grid[grid.size()-1][grid[0].size()-1];
    }
};