Java 排列和组合程序

编写一个Java程序来寻找给定值的排列和组合，并举例说明。这个Java程序接受n和r值，并使用数学公式计算出排列和组合。

Perm = 阶乘(n) / 阶乘(n - r)

Comb = 阶乘(n) / (阶乘(n - r) * 阶乘(r))

package SimpleNumberPrograms;

import java.util.Scanner;

public class Permutations {

private static Scanner sc;

public static void main(String\[\] args) {
	
	sc = new Scanner(System.in);
	int n, r, NCR, NPR;
	
	System.out.print("Please Enter n Value = ");
	n = sc.nextInt();
	System.out.print("Please Enter r Value = ");
	r = sc.nextInt();
	
	NCR = fact(n)/(fact(n - r) \* fact(r));
	NPR = fact(n)/fact(n - r);
	
	System.out.println("NCR Value = " + NCR);
	System.out.println("NPR Value = " + NPR);
}

public static int fact(int number) {
	if(number == 0 || number == 1) {
		return 1;
	}
	else {
		return number \* fact(number - 1);
	}
}