How can I implement a queue in C?

How can I implement a queue in C?

You can implement a queue in C using structures and linked lists or arrays. Which method would you prefer?

I think using linked lists would be better. Can you show me an example?

Sure! Here's a simple implementation using linked lists:

#include <stdio.h>
#include <stdlib.h>

struct Node {
    int data;
    struct Node* next;
};

struct Queue {
    struct Node* front;
    struct Node* rear;
};

struct Queue* createQueue() {
    struct Queue* q = (struct Queue*)malloc(sizeof(struct Queue));
    q->front = q->rear = NULL;
    return q;
}

void enqueue(struct Queue* q, int value) {
    struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
    temp->data = value;
    temp->next = NULL;
    if (q->rear == NULL) {
        q->front = q->rear = temp;
        return;
    }
    q->rear->next = temp;
    q->rear = temp;
}

int dequeue(struct Queue* q) {
    if (q->front == NULL) return -1;
    struct Node* temp = q->front;
    int value = temp->data;
    q->front = q->front->next;
    if (q->front == NULL) q->rear = NULL;
    free(temp);
    return value;
}

int main() {
    struct Queue* q = createQueue();
    enqueue(q, 10);
    enqueue(q, 20);
    printf("Dequeued: %d\n", dequeue(q));
    return 0;
}

This code creates a queue and demonstrates enqueue and dequeue operations.

That looks great! How do I handle memory management for the queue?

Good question! You should free the memory allocated for each node when you dequeue it. Additionally, when you're done using the queue, make sure to free all remaining nodes to prevent memory leaks.