Function creation - Datastructures - Linked Queue

[quasi marsh]

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "printer.h"
#include "queue.h"
#include "task.h"

int main()
{
    srand(time(NULL));
    struct printer *p = malloc(sizeof(struct printer));
    struct queue *q = create_queue();
    struct task *t = create_task(0);
    tick(p);
    is_busy(p);
    enqueue(q, t);
    start_next(p, t);
    free(q);
    free(t);
}

struct queue *create_queue()
{
    struct queue *myqueue = malloc(sizeof(struct queue));
    myqueue->front = NULL;
    myqueue->rear = NULL;
    return myqueue;
}

struct task *create_task(int ct)
{
    struct task *newtask = malloc(sizeof(struct task));
    newtask->pages = rand();
    newtask->time_stamp = ct;
    return newtask;
}

void enqueue(struct queue *q, struct task *t)
{
    struct node *ptr = malloc(sizeof(struct node));
    ptr->data = t;
    if (q->front == NULL)
    {
        q->front = ptr;
        q->rear = ptr;
    }
}

void tick(struct printer *p)
{
    p->time_remaining = p->time_remaining - 1;
}

int is_busy(struct printer *p)
{
    if (p->time_remaining > 0)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}
struct task *dequeue(struct queue *q)
{
    if (q->front == NULL)
    {
        printf("Queue is empty.\n");
    }
    struct node *dequeuedNode = q->front;
    struct task *dequeuedTask = dequeuedNode->data;
    q->front = q->front->next;

    free(dequeuedNode);

    return dequeuedTask;
}
void start_next(struct printer *p, struct task *t)
{

}
void printer_status(struct printer *p);

int is_empty(struct queue *q);```

[fervent adder]

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[quasi marsh]

Hi, i need some help in creating the struct task *dequeue(struct queue *q) function

How do i return a task that is within a node which is inside a queue?

[spark patrol]

What's wrong with your solution?

[quasi marsh]

It was empty when i posted it here but i decided to gpt it while i waited. Not sure if it works tho

int main()
{
    srand(time(NULL));
    int options = 0;
    struct printer *p = malloc(sizeof(struct printer));
    struct queue *q = create_queue();

    while (scanf("%d", &options) == 1)
    {
        struct task *t = create_task(0);
        is_busy(p);
        enqueue(q, t);
        start_next(p, t);
        printer_status(p);
        is_empty(q);
    }
    tick(p);
    free(q);
    free(t);
}

Why does free(t) Become undefined when my *t is within my while loop?

Isn't *t defined in main() ?

[spark patrol]

t is a variable local to the while scope, i.e. it gets destroyed and reborn in every iteration of the while loop

Which is why you can't access it anymore after the loop

[quasi marsh]

Ah ok