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=;i<grid.size();++i)
            grid[i][]+=grid[i-][];
        for(int j=;j<grid[].size();++j)
            grid[][j]+=grid[][j-];
        for(int i=;i<grid.size();++i)
        {
            for(int j=;j<grid[i].size();++j)
            {
                grid[i][j]+=min(grid[i-][j],grid[i][j-]);
            }
        }
        return grid[grid.size()-][grid[].size()-];
    }
};