Thread: What is wrong with my queue ADT?

Code:

#include "queue.h"

QUEUE* CreateQueue(void)
{
    QUEUE* queue;


    queue = (QUEUE*)malloc(sizeof(QUEUE));


    if(queue)
    {
        int count = 0;
        queue->front = NULL;
        queue->rear = NULL;
    }
    else
        return NULL;
    return queue;
}


bool Enqueue(QUEUE* queue, void* dataptr)
{
    NODE* newnode;
    
    if(!(newnode = (NODE*) malloc(sizeof(NODE))))
        return FALSE;


    newnode->dataptr = dataptr;
    newnode->next = NULL;


    if(queue->count == 0)
        queue->front = newnode;
    else
        queue->rear->next = newnode;
    (queue->count)++;
    queue->rear = newnode;
    return TRUE;
}


void* Dequeue (QUEUE* queue)
{
    void* dataOut;
    NODE* temp;
    
    if(queue->count == 0)
        return NULL;
    dataOut = queue->front->dataptr;
    temp = queue->front;
    queue->front = queue->front->next;
    if(queue->count == 1)
        queue->rear = NULL;
    (queue->count)--;
    free(temp);
    return dataOut;
}


void* QueueFront (QUEUE* queue)
{
    void* dataOut;
    
    if(queue->count == 0)
        return NULL;
    else
        return queue->front->dataptr;
}


void* QueueRear (QUEUE* queue)
{
    void* dataOut;
    if(queue->count == 0)
        return NULL;
    else
        return queue->rear->dataptr;
}


bool EmptyQueue (QUEUE* queue)
{
    return (queue->count == 0);
}    


bool FullQueue (QUEUE* queue)
{
    NODE* temp;


    temp = (NODE*)malloc(sizeof(*(queue->rear)));
    if(temp)
    {
        free(temp);
        return FALSE;
    }
    return TRUE;
}


int QueueCount(QUEUE* queue)
{
    return queue->count;
}


void DestroyQueue(QUEUE* queue)
{
    NODE* temp;
    if(queue->count != 0)
    {
        while(queue->front != NULL)
        {
            temp = queue->front;
            queue->front = queue->front->next;
            free(temp->dataptr);
            free(temp);
        }
    }
    free(queue);
}

So I tried to enqueue something very simple in main as so:

Code:

#include "queue.h"


int main(void)
{
    int* a;
    QUEUE* queue;


    queue = CreateQueue();
    a = (int*)malloc(sizeof(int));
    *a = 1;
    Enqueue(queue, a);
    return 0;
}

When I compile, the program crashes and my debugger states that there was an exception at this line:

Code:

bool Enqueue(QUEUE* queue, void* dataptr){
    NODE* newnode;
    
    if(!(newnode = (NODE*) malloc(sizeof(NODE))))
        return FALSE;


    newnode->dataptr = dataptr;
    newnode->next = NULL;


    if(queue->count == 0)
        queue->front = newnode;
    else
        queue->rear->next = newnode;
    (queue->count)++;
    queue->rear = newnode;
    return TRUE;
}

I am using Microsoft visual studio 2010.

Any help is appreciated!