Possible memory leaks

[mlholder]

Hi all, I trying to refresh some of the concepts I learned using pointers. The program I have below works as the way I would like, but I am looking to see if there are any memory leaks, especially in my exit function. Any and all help would be greatly appreciated. Thank you.

#include <iostream>
#include <string>
#include <cstring>
#include <iomanip>

const int NUM_OF_LABS(4);

void create(std::string** &);
void initialize(std::string** &);
void menu(int &);
void login(std::string** &);
void logout(std::string** &);
void display(std::string** &);
void search(std::string** &);
void exit(std::string**);

int main()
{
	using namespace std;

	int option;
	string **stations;

	create(stations);
	initialize(stations);

	do
	{
		menu(option);

		if(option == 1)
			login(stations);
		else if(option == 2)
			logout(stations);
		else if(option == 3)
			display(stations);
		else if(option == 4)
			search(stations);
		else
			exit(stations);

	}while(option != 5);

	return 0;
}

void create(std::string** &stations)
{
	using namespace std;

	int numberOfStations[NUM_OF_LABS] = { 5, 6, 4, 3 };

	stations = new string*[NUM_OF_LABS];

	for(unsigned int i = 0; i < NUM_OF_LABS; i++)
		stations[i] = new string[numberOfStations[i]];
}
void initialize(std::string** &stations)
{
	int numberOfStations[NUM_OF_LABS] = { 5, 6, 4, 3 };

	for(unsigned int row = 0; row < NUM_OF_LABS; row++)
	{
		for(unsigned int col = 0; col < numberOfStations[row]; col++)
			stations[row][col] = "empty";
	}
}
void menu(int &op)
{
	using namespace std;

	string s;

	do
	{
		cout << "Please select from the following options.\n\n"
			 << "1. Simulate login\n"
			 << "2. Simulate logoff\n"
			 << "3. Display computer stations\n"
			 << "4. Search for a user\n"
			 << "5. Exit\n\n"
			 << "Option: ";
		getline(cin, s);

		if( (s.find_first_not_of("12345") != string::npos) || (s.length() > 1) )
			cout << "The option entered is not valid!\n";

	}while( (s.find_first_not_of("12345") != string::npos) || (s.length() > 1) );

	cout << endl;

	char *temp = new char[s.length() + 1];
	strncpy(temp, s.c_str(), s.length());
	temp[s.length()] = NULL;

	op = atoi(temp);

	delete [] temp;
	temp = NULL;
}
void login(std::string** &stations)
{
	using namespace std;

	char *temp;
	int labNumber, computer;
	string s, id;

	do
	{
		cout << "Enter the 5 digit userID: ";
		getline(cin, s);

		if( (s.find_first_not_of("1234567890") != string::npos) || (s.length() != 5) )
			cout << "The userID entered is not valid!\n";

	}while( (s.find_first_not_of("1234567890") != string::npos) || (s.length() != 5) );

	id = s;

	do
	{
		cout << "Enter the lab number (1-4): ";
		getline(cin, s);

		if( (s.find_first_not_of("1234") != string::npos) || (s.length() != 1) )
			cout << "The lab number entered is not valid!\n";

	}while( (s.find_first_not_of("1234") != string::npos) || (s.length() != 1) );

	temp = new char[s.length() + 1];
	strncpy(temp, s.c_str(), s.length());
	temp[s.length()] = NULL;
	labNumber = atoi(temp);
	delete [] temp;
	temp = NULL;

	do
	{
		do
		{
			if(labNumber == 1)
				cout << "Enter the computer station (1-5): ";
			else if(labNumber == 2)
				cout << "Enter the computer station (1-6): ";
			else if(labNumber == 3)
				cout << "Enter the computer station (1-4): ";
			else
				cout << "Enter the computer station (1-3): ";

			getline(cin, s);

			if( (s.find_first_not_of("123456") != string::npos) || (s.length() != 1) )
				cout << "The computer station entered is not valid!\n";

		}while( (s.find_first_not_of("123456") != string::npos) || (s.length() != 1) );

		temp = new char[s.length() + 1];
		strncpy(temp, s.c_str(), s.length());
		temp[s.length()] = NULL;
		computer = atoi(temp);
		delete [] temp;
		temp = NULL;

		if( (labNumber == 1 && computer > 5) || (labNumber == 2 && computer > 6) || (labNumber == 3 && computer > 4) || (labNumber == 4 && computer > 3) )
			cout << "The computer station entered is not valid!\n";

	}while( (labNumber == 1 && computer > 5) || (labNumber == 2 && computer > 6) || (labNumber == 3 && computer > 4) || (labNumber == 4 && computer > 3) );
	
	stations[labNumber - 1][computer - 1] = id;
	cout << "\nLogin: Validated.\n\n";
}
void logout(std::string** &stations)
{
	using namespace std;

	bool found = false;
	int numberOfStations[NUM_OF_LABS] = { 5, 6, 4, 3 };
	string id;

	do
	{
		cout << "Enter the 5 digit userID: ";
		getline(cin, id);

		if( (id.find_first_not_of("1234567890") != string::npos) || (id.length() != 5) )
			cout << "The userID entered is not valid!\n";

	}while( (id.find_first_not_of("1234567890") != string::npos) || (id.length() != 5) );

	for(int row = 0; row < NUM_OF_LABS; row++)
	{
		for(int col = 0; col < numberOfStations[row]; col++)
		{
			if(stations[row][col] == id)
			{
				stations[row][col] = "empty";
				found = true;
				break;
			}
		}

		if(found)
			break;
	}

	cout << "Logout: Complete\n\n";
}
void display(std::string** &stations)
{
	using namespace std;

	int numberOfStations[NUM_OF_LABS] = { 5, 6, 4, 3 };

	cout << "Lab Number Computer Stations\n";

	for(unsigned int row = 0; row < NUM_OF_LABS; row++)
	{
		cout << left << setw(11) << row + 1;

		for(unsigned int col = 0; col < numberOfStations[row]; col++)
			cout << col + 1 << ": " << stations[row][col] << " ";

		cout << endl;
	}

	cout << endl;
}
void search(std::string** &stations)
{
	using namespace std;

	bool found = false;
	int r, c, numberOfStations[NUM_OF_LABS] = { 5, 6, 4, 3 };
	string id;

	do
	{
		cout << "Enter the 5 digit userID: ";
		getline(cin, id);

		if( (id.find_first_not_of("1234567890") != string::npos) || (id.length() != 5) )
			cout << "The userID entered is not valid!\n";

	}while( (id.find_first_not_of("1234567890") != string::npos) || (id.length() != 5) );

	cout << endl;

	for(unsigned int row = 0; row < NUM_OF_LABS; row++)
	{
		for(unsigned int col = 0; col < numberOfStations[row]; col++)
		{
			if(stations[row][col] == id)
			{
				r = row + 1;
				c = col + 1;
				found = true;
				break;
			}
		}

		if(found)
			break;
	}

	if(found)
		cout << "User " << id << " is in Lab " << r << " at Station " << c << endl << endl;
	else
		cout << "User " << id << " is not currently logged in.\n\n";
}
void exit(std::string** stations)
{
	for(unsigned int i = 0; i < NUM_OF_LABS; i++)
		stations[i] = NULL;

	for(unsigned int i = 0; i < NUM_OF_LABS; i++)
		delete [] stations[i];
	delete [] stations;
}

[pnoid]

Valgrind is a decent tool for checking for memory leaks.

http://valgrind.org/

[mlholder]

Thank you pnoid. I will definitely look into this.