Program:
#include <stdio.h>
#include <stdlib.h>
struct student
{
int rollno;
char name[20];
float fee;
struct student *next;
};
struct student *front = NULL;
struct student *rear = NULL;
void enqueue()
{
struct student *newstudent = (struct student *)malloc(sizeof(struct student));
if (newstudent == NULL)
printf("Overflow: Memory Full. You cant insert more items\n");
else
{
printf("\nenter student roll no: ");
scanf("%d", &newstudent->rollno);
printf("enter name: ");
fflush(stdin);
gets(newstudent->name);
printf("enter fee : ");
scanf("%f", &newstudent->fee);
newstudent->next = NULL;
if (front == NULL)
{
front = rear = newstudent;
}
else
{
rear->next = newstudent;
rear = newstudent;
}
}
}
void dequeue()
{
if (front == NULL)
printf("underflow!!!. Queue is empty. No item to delete");
else
{
struct student *ptr = front;
printf("Deleted item is :\n");
printf("Rollno\tname\tfee");
printf("\n%d\t%s\t%f\n", front->rollno, front->name, front->fee);
free(ptr);
front = front->next;
if (front == NULL)
rear = NULL;
}
}
void peek()
{
if (front == NULL)
printf("Queue is empty. No item to display");
else
{
printf("Item at the Front is :\n");
printf("Rollno\tname\tfee");
printf("\n%d\t%s\t%f\n", front->rollno, front->name, front->fee);
}
}
void display()
{
if (front == NULL)
printf("Queue is empty. No item to display");
else
{
struct student *ptr = front;
printf("\nInformation of Queue is : \n");
printf("Rollno\tname\tfee");
while (ptr != NULL)
{
printf("\n%d\t%s\t%f\n", ptr->rollno, ptr->name, ptr->fee);
ptr = ptr->next;
}
}
}
void main()
{
int ch;
printf("****************************************\n");
printf("****************************************\n");
printf("** Dynamic / Linked Queue **\n");
printf("** Using Linked Lists **\n");
printf("** Program Created By Sheetal Garg **\n");
printf("** Assistant professor **\n");
printf("** 9467863365 **\n");
printf("****************************************\n");
printf("****************************************\n");
while (1)
{
printf("\nOptions Available are\n");
printf("1. Enqueue \n");
printf("2. Dequeue \n");
printf("3. Peek \n");
printf("4. Display \n");
printf("5. Exit \n");
printf("\nEnter your choice : ");
scanf("%d", &ch);
switch (ch)
{
case 1:
enqueue();
break;
case 2:
dequeue();
break;
case 3:
peek();
break;
case 4:
display();
break;
case 5:
exit(0);
default:
printf("Wrong choice entered");
}
}
}Output:
****************************************
****************************************
** Dynamic / Linked Queue **
** Using Linked Lists **
** Program Created By Sheetal Garg **
** Assistant professor **
** 9467863365 **
****************************************
****************************************
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 1
enter student roll no: 1
enter name: Sheetal
enter fee : 1000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 1
enter student roll no: 2
enter name: Amit
enter fee : 2000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 1
enter student roll no: 3
enter name: Nidhi
enter fee : 3000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 4
Information of Queue is :
Rollno name fee
1 Sheetal 1000.000000
2 Amit 2000.000000
3 Nidhi 3000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 3
Item at the Front is :
Rollno name fee
1 Sheetal 1000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 2
Deleted item is :
Rollno name fee
1 Sheetal 1000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 4
Information of Queue is :
Rollno name fee
2 Amit 2000.000000
3 Nidhi 3000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 2
Deleted item is :
Rollno name fee
2 Amit 2000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 4
Information of Queue is :
Rollno name fee
3 Nidhi 3000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 2
Deleted item is :
Rollno name fee
3 Nidhi 3000.000000
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 4
Queue is empty. No item to display
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 2
underflow!!!. Queue is empty. No item to delete
Options Available are
1. Enqueue
2. Dequeue
3. Peek
4. Display
5. Exit
Enter your choice : 5