Codeforces竞赛解析：EducationalRound84（Div.2评级），题目A：奇数和问题

#include
#define ll long long
using namespace std;
//const int N=1e4+5;
int main(){
int T;
ios::sync_with_stdio(false);cin.tie(0);
cin>>T;
while(T--){
ll n,k;
cin>>n>>k;
if(n>=k*k&&n%2==k%2)cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
return 0;
}

#include
#define ll long long
using namespace std;
//const int N=1e4+5;
int main(){
int T;
ios::sync_with_stdio(false);cin.tie(0);
cin>>T;
while(T--){
ll n,k;
cin>>n>>k;
if((n-(k-1)*(k-1))%2&&(n-(k-1)*(k-1))>=2*k-1)cout<<"YES"<<endl;
else cout<<"NO"<<endl;
}
return 0;
}