# Segregate Odd-Even

Posted: 5 Dec, 2020
Difficulty: Moderate

## PROBLEM STATEMENT

#### A singly linked list is a type of linked list that is unidirectional; that is, it can be traversed in only one direction from head to the last node (tail).

##### Example:
``````The attendees holding numbers from 1, 4, 3 are shown:
``````

#### As the organizers are busy, you have to arrange all the people by arranging the bride’s side people first followed by the groom’s side people sequentially.

##### Note:
``````For the above example 1 -> 4 -> 3, 1 -> 3 -> 4 is the only correct answer, i.e nodes should be grouped sequentially. Hence, 3 -> 1 -> 4 is the wrong answer as we have to preserve the same order.
``````
##### Input Format
``````The first line of input contains an integer T, the number of test cases. Then each test case follows.

The first and the only line of every test case contains the elements of the singly linked list separated by a single space and terminated by -1.
Hence, -1 would never be a list element.
``````
##### Output Format:
``````For every test case, print the bride’s side attendees followed by the groom’s side attendees.
The attendees/elements should be single-space separated, terminated by -1.

The output of each test case is printed in a separate line.
``````
##### Note :
``````You don't need to print the output, it has already been taken care of. Just implement the given function.
``````
##### Constraints:
``````1 <= T <= 10
1 <= N <= 5 * 10^4
0 <= data <= 10^4 and data != -1

Where 'N' denotes the number of elements in the Singly Linked List and 'data' represents the value of those elements.

Time Limit: 1 sec
``````