Divisor differene

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll divisor_difference(ll n)
{
    ll diff, ans = n - 1;
    int sqrtN = sqrt(n) + 1;
    for(ll i = 1; i <= sqrtN; i++)
    {
        if(n % i == 0)
        {
            ll j = n / i;
            diff = abs(i - j);
            if(diff < ans)
                ans = diff;
        }
    }
    return ans;
}
int main(void)
{
    int t;
    ll n;
    cin >> t;
    for(int kase = 1; kase <= t; kase++)
    {
        cin >> n;
        printf("Case #%d: %lld\n", kase, divisor_difference(n));
    }
    return 0;
}