C language implementation of chain queue

#include "stdio.h"
#include "Stdlib.h"
#include "io.h"
#include "math.h"
#include "time.h"

#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0
#define MAXSIZE 20/* Storage space Initial allocation */

typedef int STATUS;

typedef int QELEMTYPE; /* The Qelemtype type is based on the actual situation and is assumed to be int */

typedef struct QNODE/* Node structure */
{
Qelemtype data;
struct Qnode *next;
}qnode,*queueptr;

typedef struct/* queue's Linked list structure */
{
Queueptr front,rear; /* team head, tail hands */
}linkqueue;

Status visit (qelemtype c)
{
printf ("%d", c);
return OK;
}

/* Construct an empty queue Q */
Status initqueue (Linkqueue *q)
{
Q->front=q->rear= (queueptr) malloc (sizeof (Qnode));
if (! Q->front)
Exit (OVERFLOW);
q->front->next=null;
return OK;
}

/* Destroy Queue Q */
Status destroyqueue (Linkqueue *q)
{
while (Q->front)
{
q->rear=q->front->next;
Free (Q->front);
q->front=q->rear;
}
return OK;
}

/* Clear Q to empty queue */
Status clearqueue (Linkqueue *q)
{
Queueptr p,q;
q->rear=q->front;
p=q->front->next;
q->front->next=null;
while (p)
{
Q=p;
p=p->next;
Free (q);
}
return OK;
}

/* If q is an empty queue, returns TRUE, otherwise false */
Status queueempty (Linkqueue Q)
{
if (q.front==q.rear)
return TRUE;
Else
return FALSE;
}

/* Ask for the length of the queue */
int Queuelength (Linkqueue Q)
{
int i=0;
Queueptr p;
P=q.front;
while (Q.REAR!=P)
{
i++;
p=p->next;
}
return i;
}

/* If the queue is not empty, use E to return the team header element of Q and return OK, otherwise return error */
Status GetHead (linkqueue q,qelemtype *e)
{
Queueptr p;
if (q.front==q.rear)
return ERROR;
p=q.front->next;
*e=p->data;
return OK;
}

/* Insert element e As Q's new team tail element */
Status EnQueue (Linkqueue *q,qelemtype e)
{
Queueptr s= (queueptr) malloc (sizeof (Qnode));
if (!s)/* Storage Allocation failed */
Exit (OVERFLOW);
s->data=e;
s->next=null;
q->rear->next=s;/* The new node s with element E assigned to the successor of the original team tail node, see figure ①*/
q->rear=s;/* sets the current s to the tail node of the team, rear points to s, see figure ②*/
return OK;
}

/* If the queue is not empty, delete the team header element of Q, return its value with E, and return to OK, otherwise return error */
Status DeQueue (linkqueue *q,qelemtype *e)
{
Queueptr p;
if (q->front==q->rear)
return ERROR;
p=q->front->next;/* The team head node you want to delete to p, see figure ①*/
*e=p->data;/* assigns the value of the team header node that you want to delete to E */
q->front->next=p->next;/* the successor P->next of the original team head node is assigned to the successor of the head node, see figure ②*/
if (q->rear==p)/* If the team head is the end of the team, then delete the rear point to the head node, see figure ③*/
q->rear=q->front;
Free (p);
return OK;
}

/* Output of each element in queue Q from the head to the end of the team */
Status Queuetraverse (Linkqueue Q)
{
Queueptr p;
p=q.front->next;
while (p)
{
Visit (P->data);
p=p->next;
}
printf ("\ n");
return OK;
}

int main ()
{
int i;
Qelemtype D;
Linkqueue Q;
I=initqueue (&Q);
if (i)
printf ("Successfully constructed an empty queue!\n");
printf ("is empty queue?") %d (1: Empty 0: No) ", Queueempty (q));
printf ("Queue Length is%d\n", Queuelength (q));
EnQueue (&q,-5);
EnQueue (&q,5);
EnQueue (&q,10);
printf ("Insert 3 elements ( -5,5,10), queue Length is%d\n", Queuelength (q));
printf ("is empty queue?") %d (1: Empty 0: No) ", Queueempty (q));
printf ("The elements of the queue are sequentially:");
Queuetraverse (q);
I=gethead (Q,&D);
if (I==ok)
printf ("Team head element is:%d\n", D);
DeQueue (&Q,&D);
printf ("deleted team head element%d\n", d);
I=gethead (Q,&D);
if (I==ok)
printf ("New team head element is:%d\n", D);
Clearqueue (&Q);
printf ("Empty queue, q.front=%u q.rear=%u q.front->next=%u\n", q.front,q.rear,q.front->next);
Destroyqueue (&Q);
printf ("Destroy queue, q.front=%u q.rear=%u\n", Q.front, Q.rear);

return 0;
}

C language implementation of chain queue