Basic C language implementation of the "ADT" queue

Queue.h

1 #ifndef _queue_h_2 #define_queue_h_3#include <stdbool.h>4 #defineMaxqueue 105 6 //Defining queue Types7typedefintItem;8 9 //node of the queueTentypedefstructnode one { a Item item; -     structNode *next; - }node; the  -typedefstructQueue - { -Node * front;//record the first item of a queue +Node * rear;//record the last item in a queue -     intItems//number of record items + }queue; a  at voidInitqueue (Queue *pq); - BOOLQueueisfull (ConstQueue *pq); - BOOLQueueisempty (ConstQueue *pq); - intQueueitemcount (ConstQueue *pq); - BOOLEnQueue (item item, Queue *pq); - BOOLDeQueue (Item * pitem, Queue *pq); in voidEmptythequeue (Queue *pq); -  to #endif

use_q.c/* function Function Implementation */

1#include <stdio.h>2#include <stdlib.h>3#include"queue.h"4 5 Static voidCopytonode (item item, Node * Pn)//copy content to a node6 {7Pn->item =item;8 }9 Static voidCopytoitem (Node * pn, Item * pi)//copies the item contents of an item to an item variableTen { one*pi = pn->item; a } -  - voidInitqueue (Queue * Pq)//Initialize Queue the { -Pq->front = Pq->rear = NULL;//Initialize the Queue's end-to-end pointers to null -Pq->items =0;//Initialize the number of items to 0 - } + BOOLQueueisfull (ConstQueue *Pq) - { +     returnPq->items = =maxqueue; a } at BOOLQueueisempty (ConstQueue *Pq) - { -     returnPq->items = =0; - } - intQueueitemcount (ConstQueue *Pq) - { in     returnPq->items; - } to BOOLEnQueue (item item, Queue * pq)//add an item at the end of the queue + { -Node * pnew;//to create a new node the      *     if(queueisfull (pq)) $         return false;Panax NotoginsengPnew = (Node *)malloc(sizeof(Node));//request space for a new node -     if(pnew = =NULL) the     { +fprintf (stderr,"Unable to allocate memory!\n"); a Exit (exit_failure); the     } +Copytonode (item, pnew);//Copy the item content to the new node -Pnew->next = NULL;//place the next member of the new node NULL to indicate that this is the last item in the current queue $     if(queueisempty (pq))//if the queue is empty, the new node is used as the header of the queue $Pq->front =pnew; -     Else //otherwise, Place the address of the new node in the next member of the tail item of the queue -Pq->rear->next =pnew; thePq->rear = pnew;//to use a new node as the tail item of a queue -pq->items++;Wuyi      the     return true; - } wu  - BOOLDeQueue (Item * pitem, Queue *Pq) about { $Node *pt; -     //the Pitem and PT are used to store the contents of the deleted Item. -     if(queueisempty (pq)) -         return false; a     //Copy the contents of the deleted item to the temporary pointer +Copytoitem (pq->front, pitem); thePT = pq->front; -      $Pq->front = pq->front->next; the      free(pt); thepq->items--; the     if(pq->items = =0)//When you delete the last item, you set the tail pointer and the head pointer to null at the same time.  thePq->rear =NULL; -     return true; in } the voidEmptythequeue (Queue *Pq) the { about Item dummy; the      while(!Queueisempty (pq)) theDeQueue (&dummy, pq); the}

main.c/* user Interface */

1#include <stdio.h>2#include"queue.h"3 4 intMainvoid)5 {6 Queue line;7 Item temp;8     Charch;9 TenInitqueue (&line ); onePuts"Testing the Queue interface. Type A To add a value,"); aPuts"Type D To delete a Value,and type q to Quit."); -      while(ch = GetChar ())! ='Q') -     { the         if(ch! ='a'&&ch! ='D') -             Continue; -         if(ch = ='a') -         { +printf"Interger to Add:"); -scanf"%d", &temp); +             if(! Queueisfull (&line )) a             { atprintf"putting%d into queue\n", temp); -EnQueue (temp, &line ); -             } -             Else -Puts"Queue is full!"); -         } in         Else -         { to             if(queueisempty (&line )) +Puts"Nothing to delete!"); -             Else the             { *DeQueue (&temp, &line ); $printf"%removing%d from queue\n", temp);Panax Notoginseng             } -         } theprintf"%d items in queue\n", Queueitemcount (&line )); +Puts"Type A to Add,d to Delete,q to Quit:"); a     } theEmptythequeue (&line ); +Puts"bye!"); -  $     return 0; $}

Basic C language implementation of the "ADT" queue