1327A - Sum of Odd Integers - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
#define ll long long
int main(int argc, char const *argv[])
{
    ll int t;
    cin >> t;
    while (t--)
    {
        ll int n, k;
        cin >> n >> k;
        if (n % 2 != 0 && n < 10 && k == 1)
        {
            cout << "YES\n";
        }
        else if (n % 2 == 2 && n < 3)
        {
            cout << "NO\n";
        }
        else if (n % 2 == 0 && k % 2 == 0 && k <= sqrt(n))
        {
            cout << "YES\n";
        }
        else if (n % 2 != 0 && k % 2 != 0 && k <= sqrt(n))
        {
            cout << "YES\n";
        }
        else
        {
            cout << "NO\n";
        }
    }

    return 0;
}