Unique Paths
Desicription
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.
Solution
代码语言：javascript复制class Solution{
public:
int uniquePaths(int m, int n){
int a = m - 1;
int b = n m - 2;
double res = 1;
for(int i = 1; i <= a; i )
res = res * (b - a i) / i;
return res;
}
};
