Creating Tree

#include<bits/stdc++/h>
using namespace std;
class Node
{
   public:
     Node *lchild;
     int dat;
     Node *rchild;
 };
 
 class Queue
 {
    private:  
      int front;
      int rear;
      int size;
      Node **Q;   //in queue we were pointing to an array, here we are pointing to a node
   public:
       Queue(int size)
       {
       this->size=size;
       front=rear=-1;
       Q=new Node*[this->size];
       }
       void enqueue(Node* x);
       Node* dequeue();
       void Display();
 } 
 
 class Tree
 {
     public:
       Node *root;
       Tree()
       {
         root=NULL;
       }
       void CreateTree();
       void Preorder(Node *p);
       void Postorder(Node *p);
       void Inorder(Node *p);
       void Levelorder(Node *p);
       void Height(Node *root);
 };
 void create(struct Queue *q,int size)
 {
   q->size=size;
   q->fron=q->rear=-1;
   q->Q=(int *)malloc(q->size*sizeof(int));
  } 
  
  void enqueue(struct Queue *q,int x)
  {
    if(q->rear==q->size-1)
    {
    cout<<"Queue is Full!";
    }
    else
    {
      q->rear++;
      Q[q->rear]=x;
    }
  }
  
   void dequeue(struct Queue *q)
  {
    int x=-1;
    if(q->rear==q->front)
    {
    cout<<"Queue is Empty!";
    }
    else
    {
     
     q->front++;
     x=Q[q->front]
    }
    return x;
  }
 
   void display(struct Queue *q)
   {
     for(int i=q->front+1;i<=q->rear;i++)
     cout<<Q[i]<<" ";
   }
 
 int main()
 {
    struct Queue q;
    int size;
    cout<<"Enter size";
    cin>>size;
    create(&q,size);
    
  }