LeetCode Unique Paths

最新推荐文章于 2019-05-17 11:15:21 发布

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最新推荐文章于 2019-05-17 11:15:21 发布

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原文链接：http://www.cnblogs.com/55open/p/4146593.html

本文介绍了一个算法问题：计算从网格左上角到右下角的不同路径数量，机器人只能向下或向右移动。通过使用动态规划的方法，实现了高效的路径计数。

A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below).

The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked 'Finish' in the diagram below).

How many possible unique paths are there?

class Solution {
public:
    int uniquePaths(int m, int n) {
       vector<int> vec;
       vec.clear();
       vec.push_back(1);
       
       if(m==1 || n==1)
           return 1;
           
       for(int i=1;i<m+n-2;i++)
       {
           vec.push_back(1);
           int j = vec.size()-1;
           while(j>=1)
           {
               vec[j] += vec[j-1];
               j--;
           }
       }
       return vec[m-1];
    }
};