AcWing每日一题--阶乘

https://www.acwing.com/problem/content/1383/

 1 #include<iostream>
 2 using namespace std;
 3 int main(void){
 4     int n;
 5     cin>>n;
 6     int res=1;
 7     int d2=0,d5=0;
 8     for(int i=1;i<=n;i++){
 9         int x=i;
10         while(x%2==0){
11             x/=2;
12             d2++;
13         }
14         while(x%5==0){
15             x/=5;
16             d5++;
17         }
18         res=(res*(x%10))%10;
19     }
20     int k=min(d2,d5);
21     for(int i=0;i<d2-k;i++) res=res*2%10;
22     for(int i=0;i<d5-k;i++) res=res*5%10;
23     cout<<res;
24     return 0;
25 }

标签：www,--,res,int,阶乘,d5,d2,AcWing
来源： https://www.cnblogs.com/greenofyu/p/14328653.html