Codeup 3006: 완전 제곱수 찾기

#include <iostream>
#define ll unsigned long long int

using namespace std;

ll n, a;

bool condition(ll x)
{
	if(x*x > a) return true;
	else return false;
}

ll binary_search(ll l, ll r)
{
	ll m = (l+r)/2;
	if(l == r) return (m-1)*(m-1);
	if(condition(m)) return binary_search(l, m);
	else return binary_search(m+1, r);
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	cin >> n;
	for(int i=0; i<n; i++){
		cin >> a;
		cout << binary_search(1, 2e9+1) << "\n";
	}
	
	return 0;
}