Lab7

import java.util.Scanner;

public class Test2 {
    public static long method1 (int n) {
        // n! -> n x (n-1) x (n-2) x ... x 1
        // base case adalah saat 1! -> hasilnya 1
        // reccurence case adalah saat tidak 1
        // 2! = 2 x 1
        // 3! = 3 x 2 x 1
        // 4! = 4 x 3 x 2 x 1
        // 2! = 2 x 1!
        // 3! = 3 x 2!
        // 4! = 4 x 3!

        if (n <= 1){
            return 1;
        } else {
            return n * method1(n-1);
        }
    }
    public static String method3 (int n) {
        if (n <= 1){
            return "1";
        } else {
            return n + "*" + method3(n-1);
        }
    }
    public static String method2 (int n) {
        //n! = n x n-1 x n-2 x ... x 1

        String a = "";
        System.out.print(n+"! = ");
        for (int i = n; i > 1; i--) {
            System.out.print(i+"*");
        }
        System.out.print("1");
        return a;

    }

    public static void main (String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Masukan angka: ");
        int angka = in.nextInt();

        System.out.println(angka + "! = " + method3(angka) + " = " + method1(angka));
    }
}