大数阶乘

/*
	Date:2018-9-28
	Author:Shimmer|mote
*/
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int arr[500000];
int main() {
	int n;
	while (scanf("%d", &n) != EOF) {
		memset(arr, 0, sizeof(arr));
		int m = 1;
		arr[0] = 1; arr[1] = 1;
		for (int i = 2; i <= n; i++) {
			for (int j = 1; j <= m; j++) {//m为阶乘的位数 
				arr[j] *= i;
			}
			for (int j = 1; j <= m; j++) {
				if (arr[j] > 9) { 
					arr[j+1] += arr[j]/10;
					arr[j] = arr[j]%10;
				}
				if (arr[m+1] != 0) //进位 
					m += 1;
			} 
		}
		for (int j = m; j >= 1; j--) {
			printf("%d", arr[j]);
		}
		printf("\n");
	}	
}