Queue

queue.cpp

#include <iostream>

using namespace std;

class Queue
{
  public:
    Queue(int size);
    ~Queue();

    bool enqueue(int value);
    int dequeue();

    bool is_full();
    bool is_empty();

    void print();
  protected:
    int* container;
    int count;
    int size;
};

Queue::Queue(int size)
{
  this->container = new int[size];
  this->size = size;
  this->count = 0;
}

Queue::~Queue()
{
  if (this->container != NULL)
    delete this->container;
  this->container = NULL;
}

bool Queue::enqueue(int value)
{
  if (this->is_full())
  {
    cout << "Queue overflow!" << endl;
    return false;
  }
  this->container[this->count] = value;
  this->count++;
  return true;
}

int Queue::dequeue()
{
  if (this->is_empty())
  {
    cout << "Queue lower flow!" << endl;
    return -1;
  }
  
  int result = this->container[0];

  // Move the rest of the elements
  for (int i=0; i<this->count; i++)
    this->container[i] = this->container[i+1];
  this->count--;

  return result;
}

bool Queue::is_full()
{
  return this->count == this->size;
}

bool Queue::is_empty()
{
  return this->count == 0;
}

void Queue::print()
{
  for (int i=0; i<count; i++)
    cout << this->container[i] << endl;
}

int main(int argc, char* argv[])
{
  Queue queue(10);
  queue.enqueue(1);
  queue.enqueue(2);
  queue.enqueue(3);
  queue.enqueue(4);
  queue.print();

  cout << "Dequeue" << endl;
  queue.dequeue();
  queue.print();

  cout << "Dequeue" << endl;
  queue.dequeue();
  queue.print();

  cout << "Dequeue" << endl;
  queue.dequeue();
  queue.print();

  return 0;
}