java练习题：求n的阶乘

public class Practice{
 public static long factorial1(int n){
  if(n==0||n==1){  //0或1的阶乘都是1
   return 1;
  }
  return factorial1(n-1)*n;
 }
 public static long factorial2(int n){
  long fact=1;
  for(int i=1;i<=n;i++){
   fact=fact*i;
  }
  return fact;
 }
 public static void main(String[] args){
  int n=12;
  //通过递归
  long fact1 = factorial1(n);
  //通过循环
  long fact2 = factorial2(n);
  System.out.printf("阶乘是%d%n",fact1);
  System.out.printf("阶乘是%d%n",fact2);
 }
 }