2048的升级

当n=m时则全排错，与上题一样

当n>m时，则有n-m个是排对的，剩下m个全错

import java.util.*;

public class Main {
    public static void main(String[] args)  {
        Scanner scanner=new Scanner(System.in);
        int num= scanner.nextInt();
        for (int i=0;i<num;i++){
            int n= scanner.nextInt();
            int m=scanner.nextInt();
            System.out.println(Calculate(n,m));
        }
    }
    static int Calculate(int n,int m){
        if (n==m){
            return selectWrong(n);
        }else {
            return selectTrue(n,m)*selectWrong(m);
        }
    }
    static int selectTrue(int n,int m){
        return Factorial(n)/(Factorial(m)*Factorial(n-m));
    }
    static int Factorial(int num){
        if (num==1){
            return 1;
        }else {
            return Factorial(num-1)*num;
        }
    }
    static int selectWrong(int num){
        if (num==1){
            return 0;
        } else if (num==2) {
            return 1;
        }else {
            return (num-1)*(selectWrong(num-1)+selectWrong(num-2));
        }
    }
}