queue 1.cpp

#include <stdio.h>
#define MAX_SIZE 100 
int queue[MAX_SIZE];
int front = -1; 
int back = -1; 
void enqueue(int item) {
    if (back == MAX_SIZE - 1) { 
        printf("Error: Queue is full\n"); 
        return; 
    }
    if (front == -1) { 
        front = 0; 
    }
    back++; 
    queue[back] = item; 
}


void display() {
    if (front == -1 || front > back) { 
        printf("Queue is empty\n"); 
        return; 
    }
    printf("Queue elements are: "); 
    for (int i = front; i <= back; i++) { 
        printf("%d ", queue[i]);
    }
    printf("\n"); 
}


int is_empty() {
    if (front == -1 || front > back) { // Check if the queue is empty
        return 1; 
    }
    return 0; 
}

int main() {
    printf("Initialize a queue!"); 
    printf("\nCheck the queue is empty or not? %s\n", is_empty() ? "Yes" : "No"); // Print message to check if queue is empty
    printf("\nInsert some elements into the queue:\n");
    enqueue(1);
    enqueue(2);
    enqueue(3);
    display(); 
    printf("\nInsert another element into the queue:\n"); 
    enqueue(4);
    display(); 
    printf("\nCheck the queue is empty or not? %s\n", is_empty() ? "Yes" : "No"); 
    return 0;
}