Duplicates in a sorted java array

Question

I have to write a method that takes an array of ints that is already sorted in numerical order then remove all the duplicate numbers and return an array of just the numbers

Answer 1

Since this seems to be homework I don't want to give you the exact code, but here's what to do:

• Do a first run through of the array to see how many duplicates there are
• Create a new array of size (oldSize - duplicates)
• Do another run through of the array to put the unique values in the new array

Since the array is sorted, you can just check if array[n] == array[n+1]. If not, then it isn't a duplicate. Be careful about your array bounds when checking n+1.

edit: because this involves two run throughs it will run in O(2n) -> O(n) time.