Partition It ( DSA INTERVIEW PREPARATION PROBLEMS AND SOLUTIONS )

 Chef has the 

N numbers 1,2,3,…,N. He wants to give exactly K of these numbers to his friend and keep the rest with him.

He can choose any K numbers such that the GCD of any number from Chef's set and any number from his friend's set is equal to 1.

Formally, suppose Chef gives the set of numbers A to his friend and keeps B with himself (where |A|=K and |B|=N−K). Then A and B must satisfy

gcd(a,b)=1  ∀a∈A,b∈B

Chef needs your help in choosing these K numbers. Please find any valid set of K numbers that will satisfy the condition, or tell him that no such set exists.

Input Format

  • The first line of input contains a single integer T denoting the number of test cases. The description of T test cases follows.
  • The first and only line of each test case contains two space-separated integers N and K.

Output Format

For each test case first output a single line containing "YES" (without quotes) if a set of size K satisfying Chef's condition exists; and "NO" if no such set exists. This line is not case-sensitive so "YeS", "nO", etc. are also acceptable.

Next, if the answer is "YES", print another line containing K distinct space-separated integers from 1 to N denoting the numbers which Chef will give to his friend. The integers can be printed in any order.

If there are multiple solutions, you may print any of them.

Constraints

  • 1≤T≤104
  • 2≤N≤105
  • 1≤K≤N−1
  • Sum of N over all test cases does not exceed 5∗105

Sample Input 1 

3
4 1
4 2
6 3

Sample Output 1 

Yes
3
Yes
4 2
No

Explanation

Test case 1: Chef can give [3] to his friend and keep [1,2,4] for himself. 3 is coprime with 1,2 and 4 so the condition is satisfied. Another possible solution is Chef giving [1] to his friend.

Test case 2: Chef can give [2,4] and keep [1,3] (or vice versa). It can be seen that gcd(2,1)=1, gcd(2,3)=1, gcd(4,1)=1, gcd(4,3)=1 and so the condition is satisfied.

Test case 3: There is no set of 3 numbers that can satisfy the given condition.

Previous
Next Post »