Find Duplicates in an Array

Given an array ARR of size 'N', where each integer is in the range from 0 to N - 1, identify all elements that appear more than once.

Return the duplicate elements in any order. If no duplicates are found, return an empty array.

Example:

Input:

T = 2
N = 5, ARR = [0, 3, 1, 2, 3]
N = 3, ARR = [0, 1, 2]

Output:

3

Explanation:

For the first test case, 3 is repeated. In the second test case, no duplicates are present.

Constraints:

1

Question

Given an array ARR of size 'N', where each integer is in the range from 0 to N - 1, identify all elements that appear more than once.

Return the duplicate elements in any order. If no duplicates are found, return an empty array.

T = 2
N = 5, ARR = [0, 3, 1, 2, 3]
N = 3, ARR = [0, 1, 2]

For the first test case, 3 is repeated. In the second test case, no duplicates are present.

Accepted Answer

Identify duplicate elements in an array of integers within a specified range.

Iterate through the array and keep track of the frequency of each element using a hashmap.
Return elements with frequency greater than 1 as duplicates.
Handle edge cases such as empty array or no duplicates found.
Example: For input [0, 3, 1, 2, 3], output should be [3].

SquadStack Product Engineer interview questions & answers