用 sqrt AC 了，求问为什么

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
int n,q,ans,x,y,z,a;
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0),cout.tie(0);
	cin >> q;
	while(q--){
		cin >> n;
		a = sqrt(n);
		ans = (a-1) * 3;
		x = a * a,y = a * a + a,z = a * a + a + a;
		if(n >= x) ++ans;
		if(n >= y) ++ans;
		if(n >= z) ++ans;
		cout << ans << endl; 
	}
	return 0;
}