Queue.h

#ifndef QUEUE_H
#define QUEUE_H
#include <iostream>
using namespace std;
template <typename T> class Queue {
private:
  T *arr;
  size_t capacity;
  int read;
  int write;
  size_t size;

public:
  // Constructor
  Queue() : capacity(10), read(0), write(0), size(0) { arr = new T[capacity]; }
  Queue(size_t initialCapacity) {
    capacity = initialCapacity;
    arr = new T[capacity];
    read = write = 0;
    size = 0;
  }

  // Destructor
  ~Queue() { delete[] arr; }

  // Function to enqueue an element
  void enqueue(const T &element) {
    arr[write] = element;
    write = (write + 1) % capacity;
    if (this->isFull())
    {
      read = (read - 1) % capacity;
      return;
    }
    size++;
  }

  // Function to dequeue an element
  void dequeue() {
    if (isEmpty()) {
      cerr << "Error: Queue is empty. Cannot dequeue.\n";
      return;
    }

    if (read != write) {
      read = (read + 1) % capacity;
      size--;
      // reset read and right
      if (isEmpty()) {
        read = write = 0;
      }
    }
  }

  // Function to get the element at the front of the queue
  T frontElement() const {
    if (isEmpty()) {
      cerr << "Error: Queue is empty. No front element.\n";
      exit(1);
    }
    return arr[read];
  }

  // Function to check if the queue is empty
  bool isEmpty() const { return size == 0; }

  // Function to check if the queue is full
  bool isFull() const { return size == capacity; }

  // Function to get the current size of the queue
  size_t getSize() const { return size; }

  T &operator[](size_t index) { return arr[(read + index) % capacity]; }
};

#endif // QUEUE_H