#ifndef DLIST_H
#define DLIST_H

#include <stddef.h>

struct dlist_item
{
    int data;
    struct dlist_item *next;
    struct dlist_item *prev;
};

struct dlist
{
    size_t size;
    struct dlist_item *head;
    struct dlist_item *tail;
};

// Threshold 1
struct dlist *dlist_init(void);
int dlist_push_front(struct dlist *list, int element);
void dlist_print(const struct dlist *list);
int dlist_push_back(struct dlist *list, int element);
size_t dlist_size(const struct dlist *list);

// Threshold 2
int dlist_get(const struct dlist *list, size_t index);
int dlist_insert_at(struct dlist *list, int element, size_t index);
int dlist_find(const struct dlist *list, int element);
int dlist_remove_at(struct dlist *list, size_t index);
void dlist_clear(struct dlist *list);

// Threshold 3
void dlist_map_square(struct dlist *list);
void dlist_reverse(struct dlist *list);
struct dlist *dlist_split_at(struct dlist *list, size_t index);
void dlist_concat(struct dlist *list1, struct dlist *list2);

// Threshold 4
unsigned int dlist_levenshtein(const struct dlist *list1,
                               const struct dlist *list2);

#endif /* !DLIST_H */