SimpleQueue.h

#ifndef SIMPLE_QUEUE
#define SIMPLE_QUEUE

struct Node
{
    private:
        int val;
        Node * left;
        Node * right;
    public:
        Node()
        {
            val = 0;
            left = 0;
            right = 0;
        }

        Node(int v)
        {
            val = v;
            left = 0;
            right = 0;
        }

        Node * GetLeftChild() {return left;}
        Node * GetRightChild() {return right;}
        int GetVal() {return val;}

        void SetVal(int v)
        {
            val = v;
        }

        void SetLeftChild(Node *node)
        {
            left = node;
        }

        void SetRightChild(Node *node)
        {
            right = node;
        }
};

class SimpleQueue
{
    private:
        short int state; //0 - not initialized, 1 - not full, 2 - full, 3 - empty
        int elCount;
        int capacity;
        Node ** queue;
        int pushPos;
        int popPos;

    public:
    SimpleQueue()
    {
        elCount = 0;
        state = 0;
        capacity = 0;
        pushPos = 0;
        popPos = 0;
    }

    SimpleQueue(int n)
    {
        queue = new Node* [n];
        if (queue != 0)
        {
            elCount = 0;
            capacity = n;
            state = 3;
            pushPos = 0;
            popPos = 0;
        }
        else
        {
            state = 0;
            elCount = 0;
            capacity = 0;
            pushPos = 0;
            popPos = 0;
        }
    }

    bool init(int n)
    {
        if (state == 0)
        {
            queue = new Node* [n];
            if (queue != 0)
            {
                elCount = 0;
                capacity = n;
                state = 3;
                pushPos = 0;
                popPos = 0;
                return true;
            }
            return false;
        }
    }

    bool Push(Node *el)
    {
        if (state == 1 || state == 3)
        {
            queue[pushPos++] = el;
            state = (pushPos == capacity) ? 2 : 1;
            return true;
        }
        return false;
    }

    Node *Pop()
    {
        if (state != 0 && state != 3)
        {
            state = (popPos+1 == pushPos) ? 3 : 1;
            return queue[popPos++];
        }
        return 0;
    }

    int GetState() {return state;}

    int GetCapacity(){return capacity;}

    int GetElementCount(){return elCount;}
};
#endif