Unique_Number_III.cpp

/*Unique_Number_III
Given an array that contains all elements occurring 3 times, but one occurs only once. Find that unique element.*/
#include <iostream>
using namespace std;
int main()
{
	int cnt[64] = {0};
	int n, no;
	cin >> n;
	for (int i = 0; i < n; i++)
	{
		cin >> no;

		int j = 0;
		while (no > 0)
		{
			int last_bit = (no & 1);
			cnt[j] += last_bit;
			j++;
			no = no >> 1;
		}
	}
	int p = 1;
	int ans = 0;
	for (int i = 0; i < 64; i++)
	{
		cnt[i] %= 3;
		ans += (cnt[i] * p);
		p = p << 1;
	}
	cout << ans << endl;
	return 0;
}
/*
Input : arr[] = {6, 2, 5, 2, 2, 6, 6}
Output : 5	
Time Complexity:O(n)
*/