Queue linked list prob.. need help and suggestions

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
#include<ctype.h>
#include<malloc.h>
#include<windows.h>

void clear(){
system("cls");
}

void gotoxy(int x,int y){
COORD coord;
coord.X = x;
coord.Y = y;
SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_H ANDLE),coord);
}

void enqueue();
void dequeue();
void display();

//++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++

struct node
{
int bookid; double bookprice;
char booktitle[30]; char bookauthor[30];
struct node *link;
}*start=NULL, *end=NULL, *new,*temp,*e;
typedef struct node N;

//++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++

main()
{

int ch;
do
{

clear();

gotoxy(25,7);
printf("***** ABC Booksellers *****");
gotoxy(26,8);
printf("Please select your choice:");
gotoxy(29,10);
printf("1.Enqueue / Append ");
gotoxy(29,11);
printf("2.Dequeue / Serve ");
gotoxy(29,12);
printf("3.Display");
gotoxy(29,13);
printf("4.Exit");
gotoxy(28,15);
printf("Enter your choice : ");
scanf("%d",&ch);
gotoxy(25,17);

printf("\n");

//++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++

switch(ch)
{

case 1:
clear();
enqueue();
break;

case 2:
clear();
break;

case 3:
clear();
break;

case 4:
clear();
gotoxy(32,10);
printf("THANK YOU !!!");
Sleep(3000);
clear();
printf("\n\t\t");
exit(0);

break;

default:
gotoxy(32,18);
printf("Invalid choice\n\n");
break;
}

}
while(ch<=3);
}

//++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++

void enqueue()
{
new=(N*)malloc(sizeof(N));

gotoxy(23,3);
printf("Note: Please refrain from using spaces");
gotoxy(19,4);
printf("Instead of Spaces please use a underscore.. ^_^");

gotoxy(24,7);
printf("***** Enter Book Details *****");

gotoxy(26,9);
printf("Enter Book ID: ");
scanf("%d",&new->bookid);

gotoxy(26,10);
printf("Enter Book TITLE: ");
scanf("%s",&new->booktitle);

gotoxy(26,11);
printf("Enter Book AUTHOR: ");
scanf("%s",&new->bookauthor);

gotoxy(26,12);
printf("Enter Book Price: P");
scanf("%lf",&new->bookprice);

gotoxy(14,14);
printf("Thank you, Book has been successfully appended");

Sleep(1500);

new->link=NULL;
if(end==NULL)
start=new;
else
{
e=end;
while(e->link!=NULL)
e=e->link;
e->link=new;
}
}

//++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++

void dequeue()
{
if(start==NULL)
printf("\nStack is empty\n");
else if(start->link==NULL)
{

gotoxy(28,7);
printf("***** Book Deleted *****");

gotoxy(24,9);
printf("Book ID: %d\n",start->bookid);

gotoxy(24,10);
printf("Book Title: %s",start->booktitle);

gotoxy(24,11);
printf("Book Author: %s",start->bookauthor);

gotoxy(24,12);
printf("Book Price: P%.2lf",start->bookprice);

gotoxy(24,13);
printf("Book has been successfully served!");

Sleep(1500);

free(start);
start=NULL;
}

else
{
e=end;
while(e->link!=NULL)
{
temp=e;
e=e->link;
}
gotoxy(28,7);
printf("***** Book Deleted *****");

gotoxy(24,9);
printf("Book ID: %d\n",end->bookid);

gotoxy(24,10);
printf("Book Title: %s",end->booktitle);

gotoxy(24,11);
printf("Book Author: %s",end->bookauthor);

gotoxy(24,12);
printf("Book Price: P%.2lf",end->bookprice);

gotoxy(24,13);
printf("Book has been successfully served!");

Sleep(1500);

temp->link=NULL;
free(e);
}
}


//++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++


void display()
{
if(start==NULL)
printf("\nStack is empty\n");

else
{
gotoxy(28,7);
printf("***** Stored Books *****");
e=start;
while(e!=NULL)
{

printf("\n\t\t Book ID: %d",e->bookid);
printf("\n\t\t Book Title: %s",e->booktitle);
printf("\n\t\t Book Author: %s",e->bookauthor);
printf("\n\t\t Book Price: P%.2lf\n\n",e->bookprice);

Sleep(3000);

e=e->link;
}
printf("\n");

}

}

im really getting confused olready cant seem to serve data stored.. please help me.. really need it..

http://cboard.cprogramming.com/c-pro...ead-first.html

You mean something like this....

Please note that this is incomplete....

Code:

---

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

struct node
{
  int bookid;
  double bookprice;
  char booktitle[30];
  char bookauthor[30];
  struct node *link;
};

void enqueue(struct node**);
struct node* append();
void display(struct node*);
void menu();
void cleanup(struct node*);

struct node* append(void)
{
  struct node* head = NULL;
  struct node* tail;
  int i;
  int n;

  (void)printf("How many books do you want to enter? ");
  fflush(stdout);
  scanf("%d", &n);

  enqueue(&head);
  tail = head;

  for (i = 2; i <= n; i++) {
    enqueue(&(tail->link));
    tail = tail->link;
  }

  return head;
}

void enqueue(struct node** head_ref)
{
  int bookid;
  double bookprice;
  char booktitle[30];
  char bookauthor[30];
 
  struct node* new = malloc(sizeof(struct node));

  (void)printf("Note: Please refrain from using spaces\n");
  (void)printf("Instead of Spaces please use a underscore.. ^_^\n");
  (void)printf("***** Enter Book Details *****\n");

  printf("Enter Book ID: ");
  fflush(stdout);
  scanf("%d",&bookid);
  new->bookid = bookid;

  printf("Enter Book TITLE: ");
  fflush(stdout);
  scanf("%s", booktitle);
  (void)strcpy(new->booktitle, booktitle);

  printf("Enter Book AUTHOR: ");
  fflush(stdout);
  scanf("%s",bookauthor);
  (void)strcpy(new->bookauthor, bookauthor);

  printf("Enter Book Price: ");
  fflush(stdout);
  scanf("%lf", &bookprice);
  new->bookprice = bookprice;

  new->link = *head_ref;
  *head_ref = new;

  printf("Thank you, Book has been successfully appended\n");

}

void display(struct node* head)
{
  struct node* current = head;

  while(current != NULL) {
    (void)printf("%d\n", current->bookid);
    (void)printf("%.2f\n", current->bookprice);
    (void)printf("%s\n", current->booktitle);
    (void)printf("%s\n", current->bookauthor);
    (void)printf("-------------------\n");

    current = current->link;
  }
}
void menu(void)
{
  (void)printf("***** ABC Booksellers *****\n");
  (void)printf("Please select your choice:\n");
  (void)printf("1.Enqueue / Append \n");
  (void)printf("2.Dequeue / Serve \n");
  (void)printf("3.Display \n");
  (void)printf("4.Exit \n");
  (void)printf("Enter your choice : ");
  fflush(stdout);
}

void cleanup(struct node* head)
{
  struct node *temp;

  while (head != NULL) {
    temp = head;
    head = head->link;
    free(temp);
  }
}

int main(void)
{
  int ch;
  struct node* head = NULL;

  menu();
 
  if ((scanf("%d",&ch)) == 1) {
    switch(ch)
      {
      case 1:
        head = append();
        break;

      case 2:
        break;

      case 3:
        break;

      case 5:
        printf("THANK YOU !!!\n");
        exit(0);
        break;

      default:
        printf("Invalid choice\n\n");
        break;
      }

  } else {
    (void)fprintf(stderr, "Invalid input\n");
    exit(1);
  }

  display(head);
  cleanup(head);

  exit(0);
}

---

Quote:

---

$ gcc -Wall -Wextra book.c -o book
$ ./book
***** ABC Booksellers *****
Please select your choice:
1.Enqueue / Append
2.Dequeue / Serve
3.Display
4.Exit
Enter your choice : 1
How many books do you want to enter? 3
Note: Please refrain from using spaces
Instead of Spaces please use a underscore.. ^_^
***** Enter Book Details *****
Enter Book ID: 34
Enter Book TITLE: C_Programming
Enter Book AUTHOR: someone
Enter Book Price: 19.99
Thank you, Book has been successfully appended
Note: Please refrain from using spaces
Instead of Spaces please use a underscore.. ^_^
***** Enter Book Details *****
Enter Book ID: 12
Enter Book TITLE: APUE
Enter Book AUTHOR: Stevens
Enter Book Price: 79.99
Thank you, Book has been successfully appended
Note: Please refrain from using spaces
Instead of Spaces please use a underscore.. ^_^
***** Enter Book Details *****
Enter Book ID: 15
Enter Book TITLE: Unix_Faq
Enter Book AUTHOR: Andrew
Enter Book Price: 10.00
Thank you, Book has been successfully appended
34
19.99
C_Programming
someone
-------------------
12
79.99
APUE
Stevens
-------------------
15
10.00
Unix_Faq
Andrew
-------------------
$

---