1057 N的阶乘

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 #define N 1e4
 4 int a[10010];
 5 void fancy(int x){
 6     int res = 0;
 7     a[0]=1;
 8     for(int i=1;i<=x;i++){
 9         int flag = 0;
10         for(int j=0;j<=res;j++){
11             a[j] = a[j]*i+flag;
12             flag = a[j]/10000;
13             a[j]%=10000;
14         }
15         if(flag>0){
16             a[++res] = flag;
17         }
18     }
19     printf("%d",a[res]);
20     for(int i=res-1;i>=0;i--){
21         printf("%04d",a[i]);
22     }
23     printf("\n");
24 }
25 int main(){
26     int n;
27     cin>>n;
28     fancy(n);
29     return 0;
30 }