枚举
1 #include <iostream> 2 /* 3 ID: shangca2 4 LANG: C++ 5 TASK: fact4 6 */ 7 #include<cstdio> 8 #include<cstring> 9 #include<iostream> 10 11 using namespace std; 12 int di[5000]; 13 int main() 14 { 15 freopen("fact4.in","r",stdin); 16 freopen("fact4.out","w",stdout); 17 int i,j,k,n,g=0; 18 di[0] = 1; 19 cin>>n; 20 for(i = 1 ; i <= n ; i++) 21 { 22 for(j=0 ; j <= g ; j++) 23 di[j] *= i; 24 for(j = 0 ; j <= g ; j++) 25 { 26 if(di[j]>9) 27 { 28 di[j+1] += di[j]/10; 29 di[j] = di[j]%10; 30 if(j+1>g) 31 g = j+1; 32 } 33 } 34 } 35 k=0; 36 while(di[k]==0&&k<=g) 37 k++; 38 cout<<di[k]<<endl; 39 return 0; 40 }