Remove Duplicates from Sorted Array

Remove Duplicates from Sorted Array

Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the elements should be kept the same.

Return the number of unique elements k. The first k elements of nums should hold the unique elements in their original order. Elements beyond index k do not matter.

Examples

Example 1:

Input: nums = [1, 1, 2]
Output: 2, nums = [1, 2, ...]
Explanation: The function returns k = 2, with the first 2 elements being 1 and 2.

Example 2:

Input: nums = [0, 0, 1, 1, 1, 2, 2, 3, 3, 4]
Output: 5, nums = [0, 1, 2, 3, 4, ...]
Explanation: The function returns k = 5, with the first 5 elements being 0, 1, 2, 3, and 4.

Constraints

• 1 <= nums.length <= 3 * 10^4
• -100 <= nums[i] <= 100
• nums is sorted in non-decreasing order.

Expected Complexity

• Time: O(n)
• Space: O(1)