Given an array a[] of size N which contains elements from 0 to N-1, you need to find all the elements occurring more than once in the given array.

Note: The extra space is only for the array to be returned.
Try and perform all operations within the provided array.

Example 1:

Input:
N = 4
a[] = {0,3,1,2}
Output: -1
Explanation: N=4 and all elements from 0
to (N-1 = 3) are present in the given
array. Therefore output is -1.

Example 2:

Input:
N = 5
a[] = {2,3,1,2,3}
Output: 2 3 
Explanation: 2 and 3 occur more than once
in the given array.

Your Task:
Complete the function duplicates() which takes array a[] and n as input as parameters and returns a list of elements that occur more than once in the given array in a sorted manner. If no such element is found, return list containing [-1].

Expected Time Complexity: O(n).
Expected Auxiliary Space: O(n).

Constraints:
1 <= N <= 10⁵
0 <= A[i] <= N-1, for each valid i