[LeetCode62]Unique Paths

题目：

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?

Above is a 3 x 7 grid. How many possible unique paths are there?

Note: m and n will be at most 100.

分类：Array ，DP

代码：

class Solution {
    
public:
    int uniquePaths(int m, int n) {
        vector<vector<int>> path(m,vector<int>(n,1));
        for(int i = 1;i < m; ++i)
            for(int j = 1; j < n; ++j)
            {
                path[i][j] = path[i-1][j] + path[i][j-1];
            }
        return path[m-1][n-1];
    }
};