TJPU-36 大数阶乘

#include <cstdio>
#define SIZE 6666

int main()
{
    int val;
    scanf("%d", &val);
    int ar[SIZE] = { 1 };
    for (int i = 2; i <= val; i++) {
        int carry = 0;
        for (int j = 0; j < SIZE; j++) {
            int cur_num = ar[j] * i + carry;
            ar[j] = cur_num % 10;
            carry = cur_num / 10;
        }
    }
    int index;
    for (int i = SIZE - 1; i >= 0; i--) {
        if (ar[i]) {
            index = i;
            break;
        }
    }
    for (int i = index; i >= 0; i--) {
        printf("%d", ar[i]);
    }
    putchar(‘\n‘);
    return 0;
}