Find Two Non-Repeating Elements Problem Statement

Given an array of integers ARR with size N, where exactly two elements appear only once and all others appear exactly twice, identify and return the two unique elements.

Input:

The first input line contains an integer N, the size of the array.
The second input line contains N space-separated integers representing the elements of the array.

Output:

Output two space-separated integers that appear only once, ensuring the first integer is smaller than the second.

Example:

Input:

N = 6
ARR = [2, 4, 6, 8, 4, 2]

Output:

6 8

Constraints:

• 2 <= N <= 10^5
• -10^5 <= ARR[i] <= 10^5

Note:

1. There will always be only two integers that appear exactly once, while the rest appear twice.
2. Aim to solve this problem in linear time and with constant space.