GFG FIND AN ELEMENT THAT APPEARS ONCE

#include <bits/stdc++.h>

using namespace std;
 
int getSingle(int arr[], int n) {
    int ones = 0, twos = 0;
    int common_bit_mask;

    for (int i = 0; i < n; i++) {
        twos = twos | (ones & arr[i]);
        ones = ones ^ arr[i];
        common_bit_mask = ~(ones & twos);
        ones &= common_bit_mask;
        twos &= common_bit_mask;
        printf (" %d %d n", ones, twos);
    }
 
    return ones;
}
 
int main() {
    int arr[] = { 3, 3, 2, 3 };
    int n = sizeof(arr) / sizeof(arr[0]);
    cout << "The element with single occurrence is  " << getSingle(arr, n);
    return 0;
}