hdu 1042 N!

 

#include<stdio.h>
#define nmax 100000
int num[nmax];
void solve(int n) {
    int i, j, k, r;
    for (i = 1, num[0] = 1, k = 0, r = 0; i <= n; i++) {
        for (j = 0; j <= k; j++) {
            num[j] = num[j] * i + r;
            if (num[j] >= nmax) {
                r = num[j] / nmax;
                num[j] = num[j] % nmax;
            } else {
                r = 0;
            }
        }
        if (r) {
            num[++k] = r;
            r = 0;
        }
    }
    printf("%d", num[k]);
    for (i = k - 1; i >= 0; i--) {
        printf("%05d", num[i]);
    }
    printf("\n");
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int n;
    while (~scanf("%d", &n)) {
        solve(n);
    }
    return 0;
}

import java.util.*;
import java.math.*;

public class Main {
    public static void main(String[] args) {
        int a, i;
        Scanner cin = new Scanner(System.in);
        while (cin.hasNextInt()) {
            a = cin.nextInt();
            BigInteger n = BigInteger.valueOf(1);
            if (a == 0) {
                System.out.println("1");
            } else {
                for (i = 1; i <= a; i++)
                    n = n.multiply(BigInteger.valueOf(i));
                System.out.println(n);
            }
        }
    }
}