#include "queue.h"

Queue_ptr createQueue() {
    Queue_ptr s = (Queue_ptr)malloc(sizeof(Queue));
    s->front = NULL;
    s->back = NULL;
    return s;
}

void enqueue(Queue_ptr s, element e) {
    DN_ptr n = (DN_ptr)malloc(sizeof(DLLNode));
    n->e = e;
    if (s->front == NULL) {
        n->next = NULL;
        s->front = n;
        s->back = n;
    }else{
        s->back->next = n;
        n->prev = s->back;
        s->back = n;
    }
}

element dequeue(Queue_ptr s) {
    DN_ptr temp = s->front->next;
    element e = s->front->e;
    free(s->front);
    s->front = temp;
    s->front->next = NULL;
    s->front->prev = NULL;
    return e;
}

int isEmpty(Queue_ptr s) {
    if (s->front == NULL)
        return 1;
    else
        return 0;
}

element peek(Queue_ptr s) {
    return s->front->e;
}

void display(Queue_ptr s) {
    DN_ptr temp = s->back;
    while (temp) {
        printf("%dn", temp->e);
        temp = temp->prev;
    }
}

void destroyQueue(Queue_ptr s) {
    DN_ptr temp = s->front;
    DN_ptr next;
    while (temp) {
        next = temp->next;
        free(temp);
        temp = next;
    }
    free(s);
}