Minimum Path Sum

最新推荐文章于 2019-10-26 15:10:44 发布

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最新推荐文章于 2019-10-26 15:10:44 发布

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/zengzy/p/5003774.html

本文介绍了一个使用动态规划方法解决网格路径问题的技术，寻找从左上角到右下角路径中数值之和最小的方式。通过迭代计算每个格子到起点的最小路径和，最终得出最短路径。

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.

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