WAP to find repeating elements in an array

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.

def duplicates(arr, n): d = {} res = [] for i in arr: if i in d: d[i] += 1 else: d[i] = 1 sorted_dict = dict(sorted(d.items(), key=lambda item: item[1])) for key in sorted_dict.keys(): if sorted_dict[key] > 1: res.append(key) if not res: return [-1] return sorted(res) arr=[2,9,9,7,9,2,4,5,8] n=len(arr) print(duplicates(arr, n))

[2, 9]