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AMALI 1

 

#include<stdio.h>

#include<stdio.h>

 

struct queueNode{

char data;

struct queueNode *nextptr;

};

 

typedef struct queueNode QUEUENODE;

typedef QUEUENODE*QUEUENODEPTR;

 

void printQueue(QUEUENODEPTR);

int isEmpty(QUEUENODEPTR);

char dequeue(QUEUENODEPTR*, QUEUENODEPTR*);

void enqueue(QUEUENODEPTR*, QUEUENODEPTR*, char);

void instructions(void);

 

 main {

 

QUEUENODEPTR headPtr = NULL, tailPtr = NULL;

int choice;

char item;

 

instructions();

printf("?");

scanf("%d",&choice);

while(choice!=3){

 

switch(choice){

 

case 1:

            printf("Enter a character:");

            scanf("\n%c",&item);

            enqueue(&headPtr,&tailPtr,item);

            printfQueue(headPtr);

            break;

 

case 2:

            if (lisEmpty(headptr)){

                        item = dequeue(&headPtr, &tailPtr);

                        printf("%c has been dequeued.\n",item);

                        }

 

            printfQueue(headPtr);

            break;

 

            default:

                        printf("Invalid choice\n\n");

                        instructions();

                        break;

            }

            printf("?");

            scanf("%d",&choice);

            }

 

            printf("End of run\n");

            return 0;

            }

            void instructions(void)

            {

            printf("Enter your choice:"

                                    " 1 to add an item to the queue"

                                    " 2 to remove an item from the queue"

                                    " 3 to end");

 

            void enqueue(QUEUENODEPTR *headPtr, QUEUENODEPTR *tailPtr,

                        char value)

 

            QUEUENODEPTR newPtr;

 

            newPtr=malloc(sizeof(QUEUENODE));

 

            if (newPtr!=NULL){

                        newPtr->data = value;

                        newPtr->nextPtr=NULL;

 

            if (isEmpty(*headPtr))

                        *headPtr=newPtr;

                        else

                         (*tailPtr)->nextptr=newPtr;

 

                         *tailPtr=newPtr;

                         }

                         else

                                    printf("%c not inserted. No memory available.\n",value);

                         }

                         char dequeue(QUEUENODEPTR *headPtr, QUEUENODEPTR *tailPtr)

                         {

 

                         char value;

                         QUEUENODEPTR tempPtr;

                         value=(*headPtr)->data;

                         tempPtr=*headPtr;

                         *headPtr=(*headPtr)->nextPtr;

 

                         if (*headPtr==NULL)

                                    *tailPtr=NULL;

 

                                    free(tempPtr);

                                    return value;

                         }

 

                         int isEmpty(QUEUENODEPTR headPtr)

                         {

                                    return headPtr==NULL;

                         }

 

                         void printQueue(QUEUENODEPTR currentPtr)

                         {

                                    if (currentPtr==NULL)

                                                printf("Queue is empty\n\n");

                                    else{

                                                printf("The queue is\n");

                                                while (currentPtr!=NULL){

                                                            printf("%c-->",currentPtr->data);

                                                            currentPtr=currentPtr->nextptr;

                                                }

                                                printf("NULL\n\n");

                                                }

                        }