Using Multi-dimensional Array to Simulate Linked List for STACK Construction

[abaybektursun]

This function is supposed to add a random value at the top of the stack in a valid random space of the 2D array. I can't understand what is wrong. Sometimes, when I use Push(), I do not have -1 in the first node which is supposed to be [rand][0] = random value, [rand][1] = -1,

 void Push(int list[capacity][column_number])
{

	int random_index = rand() % capacity;
	int random_value = rand();

 	for (int i = 0; i < capacity; i++)
	{
		if (/*global variable*/occupied[i] == random_index)
		{
			random_index = rand() % capacity;
			i = 0;
		}
	}

	if (Empty(list) == true)
	{
		list[random_index][0] = random_value;
		list[random_index][1] = -1;
		/*global variable*/my_top = random_index;
		/*global variable*/occupied[occupied_index] = my_top;
		/*global variable*/occupied_index++; 
		cout << "Index: " << occupied_index << " : " << list[random_index][0] << " | " << list[random_index][1] << endl;
	}
	else
	{
		list[random_index][0] = random_value;
		list[random_index][1] = my_top;
		/*global variable*/my_top = random_index;
		/*global variable*/occupied[occupied_index] = my_top;
		/*global variable*/occupied_index++;
		cout << "Index: " << occupied_index << " : " << list[random_index][0] << " | " << list[random_index][1] << endl;
	}
}

Just in case here is the full code

 
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

//Global Variables
const int capacity = 25;
const int column_number = 2;
int my_top = 0;
int occupied[capacity];
int occupied_index = 0;
//Prototypes
void Clear(int list[capacity][column_number]);
bool Empty(int list[capacity][column_number]);
void Push (int list[capacity][column_number]);

//------------MAIN-FUNCTION------------MAIN-FUNCTION---------MAIN-FUNCTION----------------
void main()
{
	//Seed for the random number generator
	srand(time(0));

	int list[capacity][column_number];
	Clear(list);

	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list); 
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list); 
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list);
	Push(list); 
	Push(list);

	for (int i = 0; i < capacity; i++)
	{
		cout << "Index: " << i << " : " << list[i][0] << " | " << list[i][1] << endl;
	}



	
	/*for (int i2 = 0; i2 < capacity; i2++)
	{
		cout << "Index: " << i2 << " | " << list[i2][0] << " | " << list[i2][1] << endl;
	}*/
}
//------------MAIN-FUNCTION------------MAIN-FUNCTION---------MAIN-FUNCTION----------------

//Function assignes value of -1 to the every single elemnt of the 2D array
//If the value of an element is -1, it is EMPTY
//(This function is not required)
void Clear(int list[capacity][column_number])
{
	for (int i = 0; i < column_number; i++)
	{
		for (int i2 = 0; i2 < capacity; i2++)
		{
			list[i2][i] = -1;
		}
	}

	for (int i = 0; i < capacity; i++)
	{
		occupied[i] = -1;
	}
}

//Function checks whether the list (stack) is empty or not
//If returns TRUE, it's empty. FALSE, if it is not
bool Empty(int list[capacity][column_number])
{
	int available_space = 0;

	for (int i = 0; i < column_number; i++)
	{
		for (int i2 = 0; i2 < capacity; i2++)
		{
			if (list[i2][i] == -1)
			{
				available_space++;
			}
		}
	}

	if (available_space == capacity*column_number/*Every single element*/)
		return true;
	else
		return false;
}

//Function adds a random value at the top of the stack
//in a valid random space of the 2D array
void Push(int list[capacity][column_number])
{

	int random_index = rand() % capacity;
	int random_value = rand();

 	for (int i = 0; i < capacity; i++)
	{
		if (occupied[i] == random_index)
		{
			random_index = rand() % capacity;
			i = 0;
		}
	}

	if (Empty(list) == true)
	{
		list[random_index][0] = random_value;
		list[random_index][1] = -1;
		my_top = random_index;
		occupied[occupied_index] = my_top;
		occupied_index++; 
		cout << "Index: " << occupied_index << " : " << list[random_index][0] << " | " << list[random_index][1] << endl;
	}
	else
	{
		list[random_index][0] = random_value;
		list[random_index][1] = my_top;
		my_top = random_index;
		occupied[occupied_index] = my_top;
		occupied_index++;
		cout << "Index: " << occupied_index << " : " << list[random_index][0] << " | " << list[random_index][1] << endl;
	}
}