Circular queue.txt

#include <stdio.h> //NAME-KINGSUK BASAK      ROLL NO - CSE2019/027
#define MAX 4      // SETTING MAX SIZE OF ARRAY TO 4.
void Insertion();  // DEFINING ALL THE FUNCTIONS USED HERE.
void Deletion();
void Display();
int queue[MAX];
int rear = -1;
int front = -1;
main()
{
    int choice; // USING A SWITCH CASE TO ASK FOR INSTRUCTIONS FROM USER.
    while (1)
    {
        printf("\nPress (1) to insert element to queue\n");
        printf("Press (2) to Delete element from queue\n");
        printf("Press (3) to Quit\n");
        printf("Enter your choice : ");
        scanf("%d", &choice);
        switch (choice)
        {
        case 1:
            printf("\n");
            Insertion();
            break;
        case 2:
            printf("\n");
            Deletion();
            break;
        case 3:
            exit(0);
        default:
            printf("\n");
            printf("Invalid choice:\n");
        }
    }
}

void Insertion() // A FUNCTION TO INSERT NEW ELEMENT AT REAR+1 AND DISPLAY THE PRESENT CONDITION OF QUEUE.
{
    int New;
    if (rear == MAX - 1)
    {
        printf("Queue Overflow\n");
    }
    else
    {
        if (front == -1)
            front = 0;
        printf("Enter element for insertion = ");
        scanf("%d", &New);
        rear = rear + 1;
        queue[rear] = New;
    }
    Display();
}

void Deletion() // FUNCTION TO DELETE ELEMENT FROM THE QUEUE BY FIFO AND DISPLAY THE PRESENT CONDITION OF QUEUE.
{
    if (front == -1 || front > rear)
    {
        printf("Queue Underflow\n");
        return;
    }
    else
    {
        printf("Element deleted from queue is : %d\n", queue[front]);
        for (int i = 0; i <= rear - 1; i++)
        {
            queue[i] = queue[i + 1];
        }
        rear = rear - 1;
    }
    Display();
}

void Display() // FUNCTION TO DISPLAY THE WHOLE QUEUE IN END OF INSERTION() OR DELETION().
{
    if (front == -1)
        printf("Queue is empty\n");
    else
    {
        printf("Present Queue is : ");
        for (int i = 0; i <= rear; i++)
            printf(" %d <-- ", queue[i]);
        printf("\n");
    }
}