Remove Duplicates from Sorted Array Problem Statement

You are given a sorted integer array ARR of size N. Your task is to remove the duplicates in such a way that each element appears only once. The output should be the length of the array after removal of duplicates.

Example:

Input:

T = 1, N = 5, ARR = [1, 1, 2, 2, 3]

Output:

3

Explanation:

The array after removing duplicates becomes [1, 2, 3], thus the length is 3.

Constraints:

1

Question

Remove Duplicates from Sorted Array Problem Statement

You are given a sorted integer array ARR of size N. Your task is to remove the duplicates in such a way that each element appears only once. The output should be the length of the array after removal of duplicates.

Example:

Input:

T = 1, N = 5, ARR = [1, 1, 2, 2, 3]

Output:

Explanation:

The array after removing duplicates becomes [1, 2, 3], thus the length is 3.

Constraints:

1 <= T <= 5
1 <= N <= 10⁵
-10⁹ <= ARR[i] <= 10⁹
Time limit: 1 sec

Note:

 - Do not allocate extra space for another array. Perform the operation in-place with O(1) extra memory.

Accepted Answer

The task is to remove duplicates from a sorted integer array in-place and return the length of the modified array.

Use two pointers, one for iterating through the array and another for keeping track of the unique elements.
Compare the current element with the next element. If they are the same, move the second pointer forward.
If they are different, update the first pointer and replace the element at the first pointer with the unique element.
Continue this process until the end of the array and return the position of the first pointer as the length of the modified array.