Queue ADT Implement Queue using Arrays C Programming.
A queue is another special kind of list, where items are
- Inserted at one end called the rear
- Deleted at the other end called the front. Operations on queues:
- enqueue: which inserts an element at the end of the
- dequeue: which deletes an element at the start of the queue
insertQ(): inserts an element at the end of queue Q. deleteQ(): deletes the first element of Q. displayQ(): displays the elements in the queue.
#include <stdio.h> #include <conio.h> # define MAX 6
void insertQ(int Q[], int *front, int *rear)
{
int data;
if((*rear) == MAX)
{
printf("\n Linear Queue is full"); return;
}
printf("\n Enter data: "); scanf("%d", &data);
Q[*rear] = data; (*rear)++;
printf("\n Data Inserted in the Queue ");
}
void deleteQ(int Q[], int *front, int *rear)
{
if(*rear == *front)
{
printf("\n\n Queue is Empty..");
*rear = *front = 0; return;
}
else
{
printf("\n Deleted element from Queue is %d", Q[*front]); (*front)++;
if( *front == *rear)
*front = *rear =0;
}
}
void displayQ(int Q[], int *front, int *rear)
{
int i;
if(*front == *rear)
{
printf("\n\n\t Queue is Empty"); return;
}
else
{
printf("\n Elements in Queue are: "); for(i = *front; i < *rear; i++)
{
printf("%d\t", Q[i]);
}
}
}
int menu()
{
int ch;
printf("\n \tQueue operations using ARRAY.."); printf("\n -----------**********---------- \n");
printf("\n 1. Insert "); printf("\n 2. Delete "); printf("\n 3. Display"); printf("\n 4. Quit ");
printf("\n Enter your choice: ");
scanf("%d", &ch); return ch;
}
void main()
{
int ch;
int Q[MAX];
int *front=0, *rear=0;
do
{
ch = menu(); switch(ch)
{
case 1:
case 2:
insertQ(Q, &front, &rear); break;
deleteQ(Q, &front, &rear); break;
case 3:
displayQ(Q, &front, &rear); break;
case 4: exit(0);
}
} while(1);
}
