http://coj.uci.cu/24h/problem.xhtml?abb=2343 "Dominoes Again!"

DominoesAgain

#include<iostream>
using namespace std;

bool test(int N,int K){
    int T;
    if(!(N%2)){
        T=  (N)*(N)/2+1;
    }
    else{
        T= (N+1)*(N)/2;
    }
    return (K<=T);
}

int main(){
    int T,N,K;
    cin >> T;
    for(int i=0;i<T;i++){
        cin >> N >> K;
        if(test(N+1,K)) cout << "Yes\n";
        else cout << "No\n";
    }
}