Rotate Linked List

Contributed by

Ayush Thakur

Medium

Avg time to solve 25 mins

Success Rate 65 %

23 upvotes

Problem Statement

You have been given a Linked List having ‘N’ nodes and an integer ‘K’. You have to rotate the Linked List by ‘K’ positions in a clockwise direction.

Example :

 Given Linked List : 1 2 3 4 -1 and K : 2
 Then the modified Linked List after K rotation : 3 4 1 2

Detailed explanation ( Input/output format, Notes, Constraints, Images )

Input Format :

The first line contains a single integer ‘T’ representing the number of test cases. 

The first line of each test case contains single space-separated integers, denoting the elements of the Linked List with -1 being the last element denoting the end of the List (or null element).

The next line of each test case contains an integer ‘K’, representing the number of positions up to the given Linked List that has to rotate.

Output Format :

For each test case, print the elements of the resultant Linked List after rotating by ‘K’ positions in a clockwise direction.

Note:

You do not need to print anything, it has already been taken care of. Just implement the given function.

Constraints :

1 <= ‘T’ <= 10
1 <= ‘N’ <= 10^5
0 <= node.data <= 10^9 and node.data != -1 
0 <= ‘K’ <= 10^5

Time Limit: 1 sec

Sample Input 1 :

2
1 2 3 4 5 6 -1
2
2 4 -1
3

Sample Output 1 :

5 6 1 2 3 4
4 2

Explanation For Sample Input 1 :

For the first test case, after 1st clockwise rotation the modified Linked List will be : 6 1 2 3 4 5
After, 2nd clockwise rotated the modified Linked List will be : 5 6 1 2 3 4

For the second test case, after 1st clockwise rotation the modified Linked List will be : 4 2
After, 2nd clockwise rotated the modified Linked List will be : 2 4
After, 3rd clockwise rotated the modified Linked List will be : 4 2

Sample Input 2 :

Sample Output 2:

2 3 1
3 6 9

Explanation For Sample Input 2 :

For the first test case, after 1st clockwise rotation the modified Linked List will be : 3 1 2
After, 2nd clockwise rotated the modified Linked List will be : 2 3 1

For the second test case, ‘K’ is 0 therefore there will be no rotation, so the Linked List remains unchanged.

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