IITKWPCO  Create Collections
Little Feluda likes to play very much. As you know he only plays with numbers. So he is given n numbers. Now tries to group the numbers into disjoint collections each containing two numbers. He can form the collection containing two numbers iff small number in the collection is exactly half of large number.
Given n numbers, Find out how many maximum number of collections he can form ?
Input
T: number of test cases. (1 <= T <= 100).
For each test case:
First line will contain n : (1 <= n <= 100)
Then next line will contain n numbers single space seperated. Range of each number will be between 1 and 10^6.
Output
For each test case, output maximum number of collections that can be formed.
Example
Input: 2
2
1 2
3
1 2 4
Output:
1
1
hide comments
shadow10:
20170817 12:06:10
WAs due to the phrase "disjoint collections".I thought duplicate items are not allowed but it is actually meant that no two collection items have same indices .Confusing problem statement. 

sameer87:
20170722 15:30:37
range in not under 10^6 :p


up79:
20170623 22:06:13
so many WA's easy one !


rajat_singhal:
20170125 07:25:00
more test case plz?? 

vineetpratik:
20160704 12:25:03
just take care of repetition, easy using map :) 

pvsmpraveen:
20160627 14:16:48
Never forget to .clear() something after each test case ;) 

mkfeuhrer:
20160621 23:03:55
simple hashing !! AC in 1 go :) take 10^7 size and use scanf...! 

gkr007:
20160602 16:30:05
@kp ur test case really helped ;) 

atulsinha007:
20160131 07:40:11
nice and easy one.. though 2 WA's :( 

goyal:
20150719 12:39:05
AC:) using maps 
Added by:  praveen123 
Date:  20130812 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  IITK ACA CSE online judge 