大数的运算--阶乘

#include <cstdio>
#include <cstdlib>
#include <cstring>
#define max_w 8002
#define base 100000

int ans[10002][max_w];
int wei[10002];

int calMulti(int n) {
    int ci = 0;
    for(int i = 0; i < wei[n-1]; i++) {
        int tmp = ans[n-1][i] * n + ci;
        ci = tmp / base;
        ans[n][i] = tmp % base; 
    }
    wei[n] = wei[n-1];
    if(ci != 0) {
        ans[n][wei[n]] = ci;
        wei[n]++;
    }
}

int show(int n) {
    printf("%d",ans[n][wei[n]-1]);
    for(int i = wei[n]-2; i >= 0; i--) {
        printf("%05d",ans[n][i]);
    }

    puts("");
}

int main(int argc, char const *argv[])
{
    memset(ans, 0, sizeof(ans));
    memset(wei, 0, sizeof(wei));
    ans[0][0] = 1;
    ans[1][0] = 1;
    wei[0] = wei[1] = 1;
    for(int i = 2; i <= 10000; i++) {
        calMulti(i);
    }
    int n;
    while(scanf("%d",&n) != EOF) {
        show(n);
        printf("%d\n",wei[10000]);
    }
    return 0;
}