Solution Kattis: Star Arrangements

https://open.kattis.com/problems/stararrangements

#include<bits/stdc++.h>
using namespace std;

int n;

bool check(int i){
 for(int j=n/i; j>=1; j--){
  if (i*j+(i-1)*j==n) return true;
  if (i*j+(i-1)*(j-1)==n) return true;
 }
 return false;
}

int main(){
 cin >> n; cout<<n<<":\n";
 for(int i=2; i<=n-1; i++){
  if (check(i)) cout<<i<<","<<i-1<<"\n";  
  if (n%i==0) cout<<i<<","<<i<<"\n";
 } 
}

Good luck! If you need help please leave a comment :)