JAVA 组合公式C（m,n)=m!/n!*(m-n)!从键盘输入两个整数x,y,求C(x,y) .要求分别用方法实现

import java.util.*;
public class Combination
{
public static void main(String[] args)
{
Vector testData = new Vector(Arrays.asList(1, 2, 3, 4, 5, 6));
Vector results = getAllCombinations(testData);
for(int i=0; i