hi
so why isnt queue printing anything where it should?
#include<iostream>
#include<string>
using namespace std;
template<class ItemType>
struct NodeType
{
ItemType info;
NodeType* next;
};
template<class ItemType>
class Queue
{
private:
int size;
NodeType<ItemType>* front; // It points to the front of a singly-linked list
NodeType<ItemType>* rear; // It points to the end of a singly-linked list
public:
Queue(); // default constructor: Queue is created and empty
Queue(const Queue<ItemType> &x); // copy constructor: implicitly called
// for a deep copy
void MakeEmpty(); // Queue is made empty; you should deallocate all
// the nodes of the linked list
bool IsEmpty(); // test if the queue is empty
bool IsFull(); // test if the queue is full; assume MAXITEM=5
int length(); // return the number of elements in the queue
void Print(); // print the value of all elements in the queue in the sequence
// from the front to rear
void Enqueue(ItemType x); // insert x to the rear of the queue
// Precondition: the queue is not full
void Dequeue(ItemType &x); // delete the element from the front of the queue
// Precondition: the queue is not empty
~Queue(); // Destructor: memory for the dynamic array needs to be deallocated
};
template<class ItemType>
Queue<ItemType>::Queue()
{
size = 0;
front = NULL;
rear = NULL;
};
template<class ItemType>
Queue<ItemType>::Queue(const Queue<ItemType> &x)
{
NodeType<ItemType>* ptr1;
NodeType<ItemType>* ptr2;
if (x.front == NULL)
{
front = NULL;
rear = NULL;
}
else // allocate memory for first node
{
front = new NodeType<ItemType>;
front->info = x.front->info;
ptr1 = x.front->next;
ptr2 = front;
while (ptr1 != NULL) // deep copy other nodes
{
ptr2->next = new NodeType<ItemType>;
ptr2 = ptr2->next;
ptr2->info = ptr1->info;
ptr1 = ptr1->next;
}
ptr2->next = NULL;
rear = ptr2;
}
};
template<class ItemType>
void Queue<ItemType>::MakeEmpty()
{
NodeType<ItemType>* tempPtr;
while (front != NULL)
{
tempPtr = front;
front = front->next;
delete tempPtr;
}
rear = NULL;
}
template<class ItemType>
bool Queue<ItemType>::IsEmpty()
{
return (size == 0);
};
template<class ItemType>
bool Queue<ItemType>::IsFull()
{
return (size >= 100);
};
template<class ItemType>
int Queue<ItemType>::length()
{
return size;
};
template<class ItemType>
void Queue<ItemType>::Enqueue(ItemType x)
{
NodeType<ItemType>* newNode;
newNode = new NodeType<ItemType>;
newNode->info = x;
newNode->next = NULL;
if (rear == NULL)
{
front = newNode;
}
else
{
rear->next = newNode;
rear = newNode;
}
size++;
};
template<class ItemType>
void Queue<ItemType>::Dequeue(ItemType &x) // removes item from the rear of the Queue // Decrements size;
{
struct NodeType<ItemType>* temp = front;
if (!IsEmpty())
{
if (front == NULL)
{
cout << "The Queue is empty." << endl;
return;
}
if (front == rear)
front = rear = NULL;
else
front = front->next;
free(temp);
}
size--;
};
template<class ItemType>
void Queue<ItemType>::Print()
{
NodeType<ItemType> *temp;
temp = front;
while (temp != NULL)
{
cout << temp->info << " " << endl;
temp = temp->next;
}
};
template<class ItemType>
Queue<ItemType>::~Queue()
{
MakeEmpty();
}
int main()
{
Queue<int>IntQueue;
int x;
IntQueue.MakeEmpty();
IntQueue.Enqueue(2);
IntQueue.Enqueue(4);
IntQueue.Enqueue(6);
IntQueue.Enqueue(8);
IntQueue.Dequeue(x);
cout << "int length 3 = " << IntQueue.length() << endl;
IntQueue.Dequeue(x);
cout << "int length 4 = " << IntQueue.length() << endl;
cout << "The int queue contains : " << endl;
IntQueue.Print();
if (IntQueue.IsFull() == false)
cout << "The int queue is not full !" << endl;
else
cout << "The int queue is full !" << endl;
Queue<string>StringQueue;
string y;
StringQueue.MakeEmpty();
StringQueue.Dequeue(y);
StringQueue.Enqueue("John");
cout << "string length 3 = " << StringQueue.length() << endl;
StringQueue.Enqueue("Brown");
cout << "string length 4 = " << StringQueue.length() << endl;
StringQueue.Enqueue("Betty");
StringQueue.Dequeue(y);
cout << "The string queue contains : " << endl;
StringQueue.Print();
Queue<string> StringQueue2 = StringQueue;
cout << "The string queue 2 contains: " << endl;
StringQueue2.Print();
StringQueue.MakeEmpty();
cout << "The string queue 3 contains: " << endl;
StringQueue2.Print();
system("pause");
return 0;
}
here is image if you cant run it
