Delete Kth Node from End of Linked List

This problem requires you to delete the Kth node from the end of a given singly linked list with N nodes containing integer data.

You are asked to efficiently remove this node.

Input:

The first integer 'T' indicates the number of test cases. For each test case, the first integer is 'K', the position (1-based index) of the node from the end to delete. The following line contains space-separated integers representing the linked list elements, ending with -1 which is not an element of the list.

Output:

For each test case, output the modified linked list, separating data with a space and ending with -1.

Example:

Input:

The given linked list is 1 - 2 - 3 - 4- 'NULL' and 'K' is 2

Output:

1 - 2 - 4 - 'NULL'

Explanation:

After removing the second node from the end, the linked list transforms to 1-2-4-'NULL'.

Constraints:

1

Question

Delete Kth Node from End of Linked List

This problem requires you to delete the Kth node from the end of a given singly linked list with N nodes containing integer data.

You are asked to efficiently remove this node.

Input:

The first integer 'T' indicates the number of test cases. For each test case, the first integer is 'K', the position (1-based index) of the node from the end to delete. The following line contains space-separated integers representing the linked list elements, ending with -1 which is not an element of the list.

Output:

For each test case, output the modified linked list, separating data with a space and ending with -1.

Example:

Input:

The given linked list is 1 -> 2 -> 3 -> 4-> 'NULL' and 'K' is 2

Output:

1 -> 2 -> 4 -> 'NULL'

Explanation:

After removing the second node from the end, the linked list transforms to 1->2->4->'NULL'.

Constraints:

1 <= 'T' <= 5
0 <= 'N' <= 10⁵
0 <= 'K' <= 'N'
1 <= 'DATA' <= 10⁹ and 'DATA' != -1

Note: You are not required to print anything; it has already been taken care of. Just implement the function. Can you solve this without finding the length of the linked list and using O(1) extra space?

Accepted Answer

To delete the Kth node from the end of a singly linked list efficiently without finding the length of the list and using O(1) extra space.

Use two pointers approach - one pointer moves K steps ahead of the other.
When the first pointer reaches the end, the second pointer will be at the Kth node from the end.
Adjust the pointers to remove the Kth node efficiently.
Ensure to handle edge cases like deleting the head or tail node.
Example: For input 1 -> 2 -> 3 -> 4 -> NULL and K = 2, output should be 1 -> 2 -> 4 -> NULL.