#include<stdio.h> #define N 10

int queue[N]; int front = -1; int rear = -1;

int enqueue(); int dequeue(); void size(); void frontElement(); void display(); void printline();

void main() { int c; do { printline(); printf("\nEnter 1.Enqueue 2.Dequeue 3.Size 4.Front Element 5. Display 6.Stop:\t"); scanf("%d", &c); printline(); switch (c) { case 1: enqueue(); break; case 2: dequeue(); break; case 3: size(); break; case 4: frontElement(); break; case 5: display(); break; case 6: printf("\nExit!!!\n"); printline(); break; default: printf("\nInvalid entry!!!\n"); printline(); } } while(c!=6); }

int enqueue() { if(rear > N-1) { printf("\nOverflow condition\n"); printline(); } else if(rear ==-1 && front ==-1) { int a; rear++; front++; printf("\nEnter the element:\t"); scanf("%d", &a); queue[rear] = a; rear++; printline(); } else { int b; printf("\nEnter the element:\t"); scanf("%d", &b); queue[rear] = b; rear++; printline(); } }

int dequeue() { if(front == -1 && rear == -1) { printf("\n\t\tUnderflow condition\n"); printline(); } else if(front > N-1) { printf("\n\t\tAll the elements are dequeued\n"); printline(); } else if(front > rear) { printf("\nAll the entered elements in the queue are dequeued. Please Enqueue\n"); } else { printf("\n\t\tThe dequeued element is %d",queue[front]); front++; printline(); } }

void size() { if(front==-1 && rear==-1) { printf("\n\t\tUnderflow condition\n"); printline(); } else if(front>N-1 || front == rear) { printf("\n\t\tThe queue elements are dequeued\n"); printline(); } else { int x; x = rear - front; printf("\n\t\tThe size of the queue is %d",x); printline(); } }

void frontElement() { if(front==-1 && rear==-1) { printf("\n\t\tUnderflow Condition\n"); printline(); } else if(front>N-1 || front == rear) { printf("\n\t\tThe queue elements are dequeued\n"); printline(); } else { int x; x = queue[front]; printf("\n\t\tThe front element is %d",x); printline(); } }

void display() { int i; if (front == -1 && rear == -1) { printf("\n\t\tUnderflow condition\n"); printline(); } else if(front > N-1 || front == rear) { printf("\n\t\tAll the elements are dequeued. No elements to display\n"); printline(); } else { printf("\n\tThe elements in the queue are:\t"); for (i = front; i < rear; i++) { printf("%d \t", queue[i]); } printline(); } }

void printline() { printf("\n------------------------------------------------------------------------------------------\n"); }