leetcode Unique Paths 2.14 难度系数2

Question：

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.

public class Solution {
  public int uniquePaths(int m, int n) {
	 
			long x = 1;
			long y = 1;
	
			if(m>n){
				for (int i = 1; i <= n - 1; i++) {
					y *= i;
				}
			
				for (int i = m; i <= m + n - 2; i++) {
					x *= i;
				}
			}else {
				for (int i = 1; i <= m - 1; i++) {
					y *= i;
				}
				
				for (int i = n; i <= m + n - 2; i++) {
					x *= i;
				}
				
			}
				return (int) (x/y);
		}
}

leetcode Unique Paths 2.14 难度系数2

原文：http://blog.csdn.net/yiding_he/article/details/18812117