Phoenix and Puzzle.cpp

// https://codeforces.com/contest/1515/problem/B
#include <bits/stdc++.h>

using namespace std;

#define fi          first
#define se          second
#define pb          push_back
#define mp          make_pair
#define all(x)      x.begin(), x.end()
#define ll          long long
#define pll         pair<long, long>
#define vll         vector<long long>
#define inf         1e18
#define gcd(a, b)   __gcd(a, b)
#define range(a,b)  substr(a,b-a+1)
#define fori(a, n)  for (ll i = a; i < n; i++)
#define forj(a, n)  for (ll j = a; j < n; j++)
#define fork(a, n)  for (ll k = a; k < n; k++)
#define print(x)    for (auto i : x) {cout << i << " ";}
#define FIO         ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)

template <class T>
bool comp(T a, T b) {
    if (a < b)
        return true;
    return false;
}

bool isPerfectSquare(long double x)
{
    if (x >= 0) {
        long long sr = sqrt(x);
        return (sr * sr == x);
    }
    return false;
}

int main()
{
    FIO;

    #ifndef ONLINE_JUDGE
    //remove this piece of code when this has to be submitted in kickstart, coding ninjas
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    //freopen is used to associate a file with stdin or stdout stream in C++
    #endif

    ll t;
    cin >> t;
    while (t--) {
        ll n;
        cin >> n;
        if (n % 2 != 0)
            cout << "NO\n";
        else {
            if (isPerfectSquare(n) || n == 2 || isPerfectSquare(n / 2))
                cout << "YES\n";
            else
                cout << "NO\n";
        }
    }

    return 0;
}