Queue appending more then one entry
I keep getting the first entry appended 4 times instead of one time.. when I append my first entry to the Queue it appends it 4 times..I thought this might be the problem..but it looks like it isn't. I can't find where the problem is..
I also created a print function for the nodes, and it showes that there are 4 of the same entries in the queue, so it is not a printing problem. And it doesn't look like it's in the read function. Maybe it's in the logic of the append function?? Still working on i开发者_如何转开发t..
This is the output: 3X^2 + 3X^2 + 3X^2 + 3X^2 + 1 but it should be 3X^2 + 1
This is my append function:
//Append(Add) item to back of queue.
Error_code Extended_queue::append(const Queue_entry &item) {
Node<Queue_entry> *new_rear = new Node<Queue_entry>(item);
if(rear == nullptr){
front = new_rear; // I also tried rear = new_rear; front = rear; rear = new_rear;
}
else {
rear->next = new_rear;
rear = new_rear;
}
return success;
}
And here is the code that prints the output:
This is the node code declaration:
#ifndef NODE_H
#define NODE_H
enum Error_code{success,underflow,overflow}; // Used in node containing classes
template <class Node_entry> // Template to allow for more varience
// Part of a linked structure
struct __declspec(align(1)) Node{
Node_entry entry; // Data contained in the node
Node *next; //Pointer to next node
//constructors
Node(); // Creates empty node
Node(Node_entry item, Node *add_on = nullptr); // Creates node with specified data and pointer to next node
};
/* Post: The Node is initialized to contain nothing, and to have a null pointer.*/
template <class Node_entry>
Node<Node_entry>::Node()
{
entry = nullptr;
next = nullptr;
}
/* Post: The Node is initialized to contain item, and to point to add_on.*/
template <class Node_entry>
Node<Node_entry>::Node(Node_entry item, Node *add_on)
{
entry = item;
next = add_on;
}
#endif
It looks like the copy constructor had bad logic. After I fixed th constructor, the driver only returned the first term as front and rear entry. So I had to fix up the overloaded = operator as well.
New Code(for copy constructor):
Extended_queue::Extended_queue(const Extended_queue &original){
Node<Queue_entry> *temp_node, *original_node = original.front;
if(original.empty()){ //original queue is empty, set new to NULL
front = nullptr;
rear = nullptr;
}
else
{
front = temp_node = new Node<Queue_entry>(original_node->entry,nullptr);
while(original_node->next != nullptr)
{
original_node = original_node->next;
//needed to change next and still incriment
temp_node->next = new Node<Queue_entry>(original_node->entry, nullptr);
temp_node = temp_node->next;
//rear->next = temp_node;
//rear = temp_node;
}
rear = temp_node->next;
}
}
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