SDE - 2

You are given a sorted integer array 'arr' of size 'n'.

You need to remove the duplicates from the array such that each element appears only once.

Return the length of this new array.

Note:

Do not allocate extra space for another array. You need to do this by modifying the given input array in place with O(1) extra memory. 

For example:

'n' = 5, 'arr' = [1 2 2 2 3].
The new array will be [1 2 3].
So our answer is 3.

Given a singly linked list of integers. Your task is to return the head of the reversed linked list.

For example:

The given linked list is 1 -> 2 -> 3 -> 4-> NULL. Then the reverse linked list is 4 -> 3 -> 2 -> 1 -> NULL and the head of the reversed linked list will be 4.

Follow Up :

Can you solve this problem in O(N) time and O(1) space complexity?

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