N!

#include <iostream>
# include <cstdio>

using namespace std;

int main()
{
    int n;
    int a[9000];
    int carry;//保存进位
    int digit = 1;//保存位数
    int temp;//阶乘任意以为与临时数组中某一位的乘积

    a[0] = 1;
    scanf("%d",&n);

    for(int i=2;i<=n;i++){//n!
        int j;
        for(j=1,carry=0;j<=digit;j++){
            temp = a[j-1]*i + carry;
            a[j-1] = temp%10;
            carry = temp/10;
        }

        while(carry){//目的是把进位保存在数组中
            a[++digit-1] = carry%10;
            carry = carry/10;
        }
    }

    for(int i=digit-1;i>=0;i--){
        printf("%d",a[i]);
    }

    printf("\n");




    return 0;
}