C++ :

#include <iostream>
#include <vector>

using namespace std;


void Process(int n)
{
	int sum;

	vector<int>v;	

	v.push_back(1);
	
	for (int i = 2; i <= n; i++)
	{
		sum = 0;
		for (int j = 0; j < v.size(); j++)
		{
			sum = v[j] * i + sum;
			v[j] = sum %10;
			sum = sum /10;
		}
		
		while (sum >0)
		{
			v.push_back(sum%10);
			sum = sum /10;
		}
	}

	vector<int>::reverse_iterator rit;//倒转输出阶乘数值
	for (rit=v.rbegin(); rit!=v.rend(); rit++)
		cout<<*rit;	
}


int main()
{
	int n;
	while (cin>>n)
	{
		Process(n);
		cout<<endl;
	}
    return 0;
}

Java :

import java.util.*;
import java.math.BigInteger;
public class Main{
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        while(input.hasNextInt()){
            int n = input.nextInt();
            String a = "2";
            String b = "1";
            for(int i = 1;i < n;i++){
                b = xx(b,a);
                a = yy(a,"1");
            }
            System.out.println(b);
        }
    }
    public static String xx(String x,String y){
        BigInteger result=null;
        BigInteger bigX=new BigInteger(x);
        BigInteger bigY=new BigInteger(y);
        result=bigX.multiply(bigY);
        return result.toString();
    }
    public static String yy(String x,String y){
        BigInteger result=null;
        BigInteger X=new BigInteger(x);
        BigInteger bb= new BigInteger(y);
        result = X.add(bb);
        return result.toString();
    }
}