#include <iostream> #include <cstring> using namespace std; int main(){ int n,i,j; cin>>n; int len=1; int m[10000]={1}; for(i=1;i<=n;i++){ for(j=0;j<len;j++){ m[j]=m[j]*i; } len=len+4; for(j=0;j<len;j++){ if(m[j]>=10){ m[j+1]=m[j+1]+m[j]/10; m[j]=m[j]%10; } } while(m[len-1]==0){ len--; } } int flag=0; for(i=len;i>=0;i--){ if(m[i]!=0){ flag=1; } if(flag==1){ cout<<m[i]; } } } /************************************************************** Problem: 1285 User: admin Language: C++ Result: Accepted Time:20 ms Memory:2072 kb ****************************************************************/