101 lines
2.2 KiB
C
101 lines
2.2 KiB
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#define MAX 5
|
|
|
|
int queue[MAX];
|
|
int front = -1;
|
|
int rear = -1;
|
|
|
|
// Different from normal queue: Need to check if (rear+1)%MAX == front for full condition
|
|
int isFull() {
|
|
if((rear + 1) % MAX == front)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
// Different from normal queue: Both front and rear can wrap around to 0
|
|
int isEmpty() {
|
|
if(front == -1)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
void enqueue() {
|
|
int item;
|
|
if(isFull()) {
|
|
printf("\nQueue is Full!!");
|
|
}
|
|
else {
|
|
printf("\nEnter element to insert: ");
|
|
scanf("%d", &item);
|
|
// Different from normal queue: rear wraps around using modulo
|
|
if(front == -1) {
|
|
front = rear = 0;
|
|
}
|
|
else {
|
|
rear = (rear + 1) % MAX;
|
|
}
|
|
queue[rear] = item;
|
|
printf("\nElement inserted successfully!");
|
|
}
|
|
}
|
|
|
|
void dequeue() {
|
|
if(isEmpty()) {
|
|
printf("\nQueue is Empty!!");
|
|
}
|
|
else {
|
|
printf("\nDeleted element is: %d", queue[front]);
|
|
// Different from normal queue: front wraps around using modulo
|
|
if(front == rear) {
|
|
front = rear = -1;
|
|
}
|
|
else {
|
|
front = (front + 1) % MAX;
|
|
}
|
|
}
|
|
}
|
|
|
|
void display() {
|
|
int i;
|
|
if(isEmpty()) {
|
|
printf("\nQueue is Empty!!");
|
|
}
|
|
else {
|
|
printf("\nQueue elements are: ");
|
|
// Different from normal queue: Need to use modulo to wrap around while displaying
|
|
for(i = front; i != rear; i = (i + 1) % MAX) {
|
|
printf("%d ", queue[i]);
|
|
}
|
|
printf("%d", queue[i]);
|
|
}
|
|
}
|
|
|
|
int main() {
|
|
int choice;
|
|
while(1) {
|
|
printf("\n\n1. Insert");
|
|
printf("\n2. Delete");
|
|
printf("\n3. Display");
|
|
printf("\n4. Exit");
|
|
printf("\nEnter your choice: ");
|
|
scanf("%d", &choice);
|
|
|
|
switch(choice) {
|
|
case 1:
|
|
enqueue();
|
|
break;
|
|
case 2:
|
|
dequeue();
|
|
break;
|
|
case 3:
|
|
display();
|
|
break;
|
|
case 4:
|
|
exit(0);
|
|
default:
|
|
printf("\nInvalid choice!!");
|
|
}
|
|
}
|
|
return 0;
|
|
}
|