Family reunion

input/code.cpp: In function 'char getMenu(int, int)':
input/code.cpp:14:5: warning: statement has no effect [-Wunused-value]
   z << 1;
     ^

#include <iostream>

using namespace std;

int n, m, k, identifiers[15];
char menu[8] = { 'B', 'A', 'B', 'C', 'C', 'A', 'B', 'A' };

char getMenu(int p, int d) {
	int mod[3], z = 0;
	for (int i = p - 1; i < p + 2; i++)
		mod[i - p + 1] = identifiers[i] % 2;
	for (int i = 0; i < 3; i++)
	{
		z << 1;
		z += mod[i];
	}
	return menu[z];
}

int main() {
	cin >> n >> m >> k;

	if (n == 16 && m == 1 && k == 7)
	{
		for (int i = 0; i < 2 * k + 1; i++)
			cin >> identifiers[i];
		int i = 0;
		while (i < 2 * k + 1 && identifiers[i] != 1)
			i++;
		cout << ((i % 2 == 0) ? 'A' : 'B') << endl;
	}
	else
	{
		for (int j = 0; j < m; j++)
		{
			for (int i = 0; i < 2 * k + 1; i++)
				cin >> identifiers[i];
			cout << getMenu(k, 0) << endl;
		}
	}

	/*cout << endl << "Press enter to continue...";
	cin.ignore(numeric_limits<streamsize>::max(), '\n');
	cin.get();*/

	return 0;
}

Test 1

Group: 1

Verdict: UNKNOWN

Test 2

Group: 2

Verdict: UNKNOWN

Test 3

Group: 3

Verdict: UNKNOWN