TQC+ JAVA

JPA04.java

import java.util.Scanner;
public class JPA03 {
    static Scanner keyboard = new Scanner(System.in);
    public static void main(String[] args) {
		System.out.print("Input n (0 <= n <= 16):");
		int num = keyboard.nextInt();
		int sum = 1;
		while(true) {
			if(num > 16 || num < 0 || num == 999) {
				break;
			}
			System.out.println(num + " 的階乘 = " + factorial(num, sum));
			System.out.print("Input n (0 <= n <= 16):");
			num = keyboard.nextInt();
		}
    }
	public static int factorial(int num, int sum) {
		if(num == 0) {
			return sum;
		}
		return factorial(num-1, num * sum);
	}
}