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. Return the answer in ascending order. If no such element is found, return list containing [-1].
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:
There is no repeating element in the 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.
Expected Time Complexity: O(n).
Expected Auxiliary Space: O(n).
Constraints:
1 <= N <= 105
0 <= A[i] <= N-1, for each valid i