小丁的試驗

小丁的試驗

Time Limit: 1 Seconds     Memory Limit: 32768 K

Total Submit:179     Accepted:51

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Description

Description

In summer holiday of Grade 1,honghu was trainning at ZOJ too. There was one problem let him remember time and time again. Now it comes :)

小丁的老師給他佈置了一個試驗,有n個燈,編號爲1,2,....n,對這n個燈做n次變化,第i(1<=i<=N)次使編號是i倍數的燈的狀態發生改變(即從暗到亮或者從亮到暗),要求記錄下最後燈的狀態是暗的個數t.已知每一個燈初試狀態都是暗的.由於小丁比較粗心,所以要求你對他給出的n和t做出判斷,看是否正確.

Input

一個正整數T,表示數據的組數,接下去的T行,每一行有兩個整數,表示n和t,其中2<=n<=500000,0<=t<=100000

Output

如果正確,輸出YES,否則輸出NO

Sample Input

2
4 2
10 6

 

Sample Output

YES
NO

 

Source:

#include<iostream.h>
int main()
{
  int n,s,m,i,j,k;
  cin>>m;
  while(m--)
  {
    cin>>n>>s;
   i=3;j=5;k=1;
   while(i<n)
	   {
		   i=i+j;
		   j=j+2;
		   k++;
	   }
  if(s==n-k)
	  cout<<"YES"<<endl;
  else
	  cout<<"NO"<<endl;
  }
	return 0;
}