Data structure-a single-chain queue-related operation algorithm

#include <stdio.h>
#include <stdlib.h>

#define OVERFLOW-2
#define OK 1
#define ERROR 0

typedef int QELEMTYPE;

Single-stranded queue structure definition
typedef struct QNODE {
Qelemtype data;
struct Qnode *next;
}qnode,*queueptr;
typedef struct {
Queueptr Front;
QUEUEPTR Rear;
}linkqueue;

When all custom functions are written in front of the main function, it is not necessary to declare each function; When the main function is written first, all the custom functions are declared before the main function.

//function declaration (not declared at this time)
int Initqueue (Linkqueue *q);//Initialize Queue
int Destoryqueue (Linkqueue *q);//Destroy queue
int Emptyqueue (Linkqueue *q);//Determine if the queue is empty
int EnQueue (Linkqueue *q,qelemtype e);//Insert Element e as a new tail element of Q
int DeQueue (linkqueue *q,qelemtype *e);//delete the team header element of the non-empty queue and return the value of the deleted element with E
int Clearqueue (Linkqueue *q);//Empty queue
int Queuelength (Linkqueue *q);//Get the length of the queue
int GetHead (linkqueue *q,qelemtype *e);//Get Team head element
void visit (Qelemtype e);//Custom visit function, representing the value of the output element
void Queuetraverse (Linkqueue *q,void *visit (Qelemtype));//Call visit function on each element in queue Q from the head to the end of the team

//Initialize queue
int Initqueue (Linkqueue *q) {
Q->front = Q->rear = (queueptr) malloc (sizeof (Qnode));
if (! Q->front) exit (OVERFLOW);
Q->front->next = NULL;
return OK;
}

//Destroy queue
int Destoryqueue (Linkqueue *q) {
while (Q->front) {
Q->rear = q->front->next;
Free (Q->front);
Q->front = q->rear;
}
return OK;
}

//Determines whether the queue is empty, returns 1 for null, and returns 0 without null
int Emptyqueue (Linkqueue *q) {
if (Q->front = = q->rear) {
return OK;
} else {
return ERROR;
}
}

//Insert element E for Q's new team tail element
int EnQueue (Linkqueue *q,qelemtype e) {
Queueptr p;
p = (queueptr) malloc (sizeof (Qnode));
if (!p) exit (OVERFLOW);
P->data = e;
P->next = NULL;
Q->rear->next = p;
Q->rear = p;
return OK;
}

//Delete the team header element of the non-empty queue and return the value of the deleted element with E
int DeQueue (linkqueue *q,qelemtype *e) {
Queueptr p;
if (Q->front = = q->rear) return ERROR;
p = q->front->next;
*e = p->data;
Q->front->next = p->next;
if (q->rear = = p) {
Q->rear = q->front;
Q->front->next = NULL;
}
Free (p);
return OK;
}

//Empty queue
int Clearqueue (Linkqueue *q) {
Queueptr p,q;
if (! Emptyqueue (Q)) {
p = q->front->next;
while (P!=q->rear) {
Q = p;
Q->front->next = p->next;
p = p->next;
Free (q);
}
Free (p);
Q->rear = q->front;
return OK;
} else {
return ERROR;
}

}

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

//Get team head element
int GetHead (linkqueue *q,qelemtype *e) {
if (! Emptyqueue (Q)) {
*e = q->front->next->data;
return OK;
} else {
return ERROR;
}
}

//Custom visit function that represents the value of the output element
void visit (Qelemtype e) {
printf ("%d", e);
}

//From the team head to the end of the queue call the visit function for each element in the queues Q
void Queuetraverse (Linkqueue *q,void *visit (qelemtype)) {
Queueptr p;
p = q->front->next;
printf ("The elements in the queue are:");
while (p) {
Visit (P->data);
p= p->next;
}
printf ("\ n");
}

int main ()
{
Linkqueue *link;
int f1,f2,f3,f4,f5,f6,e,i,a,len,n;

//Queue initialization
F1 = initqueue (link);
if (F1) printf ("Queue initialization succeeded!") \ n ");
else printf ("Queue initialization failed!") \ n ");

//Queue
printf ("Please enter the number of elements in the queue:");
scanf ("%d", &n);
printf ("Please enter the value of the element in the queue:");
for (i=0; i<n; i++) {
scanf ("%d", &a);
EnQueue (Link,a);
}

//Get Queue Length
Len = queuelength (link);
printf ("Queue Length:%d\n", Len);

//Determine if the queue is empty
F2 = emptyqueue (link);
if (F2) printf ("Queue is empty!") \ n ");
else printf ("The queue is not empty!") \ n ");

//Traversal queue
Queuetraverse (Link,&visit);

//OUT Team
F3 = DeQueue (link,&e);
if (F3) printf ("Deleted team header element is:%d\n", e);
else printf (the queue is empty!) Unable to delete team header element! \ n ");

//Get team head element
F4 = GetHead (link,&e);
if (F4) printf ("Team head element:%d\n", e);
else printf (the queue is empty!) ");

//Empty queue
F6 = clearqueue (link);
if (f6) printf ("Empty queue succeeds!") \ n ");
else printf ("Empty queue failed!") \ n ");

//Destroy queue
F5 = destoryqueue (link);
if (F5) printf ("Destroy queue succeeded!") \ n ");
else printf ("Destroy queue failed!") \ n ");

return 0;
}

Data structure-a single-chain queue-related operation algorithm