leetcode-Unique Paths

Difficulty: Medium

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.

class Solution {public:    int uniquePaths(int m, int n) {        if(m==0&&n==0)            return 0;        int path[m][n];                    for(int i=0;i<m;++i)            path[i][0]=1;                    for(int i=0;i<n;++i)            path[0][i]=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];        }};