UVa - 10892 LCM Cardinality

#include<bits/stdc++.h>
#include<vector>
#include<cmath>
#define ll long long

using namespace std;

ll gcd(ll a,ll b)
{
 return b? gcd(b,a%b):a; 
}

ll lcm(ll a,ll b)
{
 return (a*b/gcd(a,b));
}

int main()
{
 ll n,sq,m,count;
 


 while(cin>>n)
 {
  vector<ll>fact;
  if(n==0) break;
  sq = sqrt(n);
  
  for(ll i=1; i<=sq; i++)
  {
   if(n%i==0)
   {
    fact.push_back(i);
    fact.push_back(n/i);
   }
  }
  
  if(sq*sq==n) fact.pop_back();
  
  count=0;
  ll vsize = fact.size();
  
  for(ll i=0; i<vsize; i++)
  {
   for(ll j=i; j<vsize; j++)
   {
    if(lcm(fact[i],fact[j])==n) count++;
   }
  }
  
  cout<<n<<" "<<count<<endl;

  
 }
}