#include <iostream> #include <cmath> using namespace std; int sum(int n){ int s,i; s=0; for(i=2;i<=sqrt(n);i++){ if(n%i==0){ if(i==n/i){ s=s+i; }else{ s=s+i+n/i; } } } return s; } void shudui(int n){ int i,s; for(i=2;i<=n;i++){ s=sum(i); if(sum(s)==i&&i!=s&&s<=n){ cout<<i<<" "<<s<<endl; } } } int main(){ int n; cin>>n; shudui(n); } /************************************************************** Problem: 1140 User: admin Language: C++ Result: Accepted Time:14 ms Memory:2072 kb ****************************************************************/