DSA problem
Remove Duplicates from Sorted Array II
Given an integer array nums sorted in non-decreasing order, remove some duplicates in-place such that each unique element appears at most twice. The relative order of the elements should be kept the same.
Since it is impossible to change the length of the array in some languages, you must instead place the result in the first part of the array nums. More formally, if there are k elements after removing the duplicates, then the first k elements of nums should hold the final result. It does not matter what you leave beyond the first k elements.
Return k after placing the final result in the first k slots of nums. You must do this by modifying the input array in-place with O(1) extra memory.
Examples
nums = [1,1,1,2,2,3]5, nums = [1,1,2,2,3,_]nums = [0,0,1,1,1,1,2,3,3]7, nums = [0,0,1,1,2,3,3,_,_]Constraints
- 1 <= nums.length <= 3 * 10^4
- -10^4 <= nums[i] <= 10^4
- nums is sorted in non-decreasing order.
3 hints and a full solution walkthrough with step-by-step visualizations are available in the practice editor.