DSA problem
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. Then return the number of unique elements in nums.
Consider the number of unique elements of nums to be k. To be accepted, your solution must do the following:
- Change the array
numssuch that the firstkelements ofnumscontain the unique elements in the order they were present innumsinitially. - The remaining elements of
numsare not important, as well as the size ofnums. - Return
k.
The judge will verify the first k elements of your modified array against the expected answer, so you cannot allocate a new array for the result.
Examples
Example 1
Input:
nums = [1,1,2]Output:
2, nums = [1,2,_]Explanation: Your function should return k = 2, with the first two elements of nums being 1 and 2 respectively. It does not matter what you leave beyond the returned k.
Example 2
Input:
nums = [0,0,1,1,1,2,2,3,3,4]Output:
5, nums = [0,1,2,3,4,_,_,_,_,_]Explanation: Your function should return k = 5, with the first five elements of nums being 0, 1, 2, 3, and 4 respectively.
Constraints
- 1 <= nums.length <= 3 * 10^4
- -100 <= nums[i] <= 100
- 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.