Explanation: Total number of unique elements are 3, i.e[1,2,3] and Therefore return 3 after assigning [1,2,3] in the beginning of the array. Explanation: Total number of unique elements are 4, i.e[1,2 ...

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.