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

typedef struct node {
    int value;
    struct node *prev;
    struct node *next;
}node;

node *head=NULL;
node *last=NULL;
node *current=NULL;

int empty(){
    if(head==NULL)return 1;
    return 0;
}
int size(){
    int licznik=0;
    current=head;
    while(current!=NULL){
        licznik++;
        current=current->next;
    }
    return licznik;
}
void clear(){ //POPRAWIC NA GLOBALNA!!!!!!!!

    while(head!=NULL){
        node *tmp=head;
        head=head->next;
        free(tmp);
    }
    last=head;
}

void push_front(int t)
{
    node *tmp=NULL;
    tmp=malloc(sizeof(node));
    if(head==NULL && last == NULL)
    {
        head=tmp;
        last=tmp;
        tmp->value=t;
        tmp->next=NULL;
        tmp->prev=NULL;
    }
    else {
        tmp->value = t;
        tmp->next = head;
        tmp->prev = NULL;
        head->prev = tmp;
        head = tmp;
    }
}

void push_back(int t)// nie dziala
{
    node *tmp=NULL;
    tmp=malloc(sizeof(node));
    tmp->value=t;
    if(head==NULL && last == NULL)
    {
        head=tmp;
        last=tmp;
        tmp->next=NULL;
        tmp->prev=NULL;
    }
    else {
        tmp->next = NULL;
        tmp->prev = last;
        last->next = tmp;
        last = tmp;
    }
}
void remove1(int t)
{
    node *guardian=malloc(sizeof(node));
    guardian->next=head;
    node *p=guardian;
    node *q=head;
    while(q!=NULL)
    {
        if(q->value==t)
        {
            p->next=q->next;
            q->next->prev=p;
            free(q);
            q=p->next;
        }
        else{
            p=q;
            q=q->next;
        }
    }
    head=guardian->next;
    p=guardian;
    while(p->next!=NULL)p=p->next;
    if(p==guardian)last=NULL;
    else last=p;
}
int front(){
    if(head==NULL)return -1;
    return head->value;
}
int back()
{
    if(last==NULL)return -1;
    return last->value;
}
void pop_front()
{
    node *tmp=head;
    if(head==NULL) return;
    head=head->next;
    free(tmp);
}
void pop_back()
{
    node *tmp=last;
    if(last==NULL)return;
    last=last->prev;
    free(tmp);
}
void print()
{
    current=head;
    while(current!=NULL)
    {
        printf("%d ",current->value);
        current->next;
    }
}
int main() {
    printf("Hello, World!\n");
    for(int i=1;i<5;i++)
    {
        push_front(i);
    }
    push_back(6);
    remove1(4);
    while(head!=NULL)
    {
        printf("%d ",head->value);
        head=head->next;
    }


    return 0;
}