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POAccess Violation Writing in a 2 way queue
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copied!<p>I'm trying to create a two sided queue with c++. I'm using Visual Studio 2012 and keep getting: </p> <p><code>First-chance exception at 0x00D95A29 in Console_Assignment1.exe: 0xC0000005: Access violation writing location 0x00000008.</code></p> <p>I think i'm having a pointer issue (might be trying to dereference something i shouldn't). so far i have had zero luck finding the problem and i'd really appreciate a second look.</p> <p>(The code is too long to paste so i'll just copy the functions i think are giving me the problem.) Maybe just a small overview. I have a node class that holds two pointer to node (next and previous) and an int (value). and a queue class that holds two pointers to node (first and last) and an int (size).</p> <pre><code>// enqueueBeg - adds a new node at the beginning of the queue. void DBL_Queue::enqueueBeg(int insert_val) { node* new_node = new node(insert_val); // Creates the new node. new_node->setNext( this->getFirst() ); // Connects the new node to the first in the queue this->getFirst()->setPrev( new_node ); // Connects the first node in the queue to the new one this->setFirst( new_node ); // Sets the new node as the first in the queue this->setSize ( this->get_queue_size() + 1 ); // adds 1 to the size of the list // dequeueBeg - removes the first node of the queue. int DBL_Queue::dequeueBeg() { int ret_value = this->getFirst()->getVal(); node* old_node = this->getFirst(); this->setFirst( this->getFirst()->getNext() ); // Sets the second node in the queue as the first. this->getFirst()->setPrev( NULL ); // Removes the link between the new first new and the old one. this->setSize( this->get_queue_size() - 1); // Removes 1 from queue size delete old_node; // Deletes the node that use to be first. return ret_value; // Returns the value of the old node. // DBL_Queue Destructor DBL_Queue::~DBL_Queue() { if (this->first == NULL) // if queue is empty do nothing return; else { while (this->first->getNext() != NULL) // go through all nodes and delete them one by one { node* deletion = this->getFirst(); this->setFirst( this->getFirst()->getNext() ); delete deletion; } } } </code></pre> <p>Thanks in advance for the help!</p>

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