How to efficiently remove duplicates from an array without using Set
you can take the help of Set collection
int end = arr.length;Set<Integer> set = new HashSet<Integer>();for(int i = 0; i < end; i++){ set.add(arr[i]);}now if you will iterate through this set, it will contain only unique values. Iterating code is like this :
Iterator it = set.iterator();while(it.hasNext()) { System.out.println(it.next());}
If you are allowed to use Java 8 streams:
Arrays.stream(arr).distinct().toArray();
Note: I am assuming the array is sorted.
Code:
int[] input = new int[]{1, 1, 3, 7, 7, 8, 9, 9, 9, 10};int current = input[0];boolean found = false;for (int i = 0; i < input.length; i++) { if (current == input[i] && !found) { found = true; } else if (current != input[i]) { System.out.print(" " + current); current = input[i]; found = false; }}System.out.print(" " + current);output:
1 3 7 8 9 10