Double linked List functions - Driver program failure - c

Question

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
typedef struct node_t{
int value;
struct node_t *prev;
struct node_t *next;
} Node;
typedef struct LinkedList{
Node *head;
Node *tail;
} LinkedList;
void clearing_space_for_LinkedList(LinkedList *ll){
ll->head = NULL;
ll->tail = NULL;
}
int empty_check(LinkedList *ll){
if(ll->head == NULL){
return 1;
}
else{
return 0;
}
}
void add_element_at_the_beginning(LinkedList *ll, int new_value){
Node *temporary = calloc(1,sizeof(Node));
temporary->value = new_value;
if (empty_check(ll)){
temporary->next = NULL;
temporary->prev = NULL;
ll->head = temporary;
ll->tail = temporary;
}
else{
temporary->next = ll->head;
temporary->prev = NULL;
ll->head->prev = temporary;
ll->head = temporary;
}
}
void add_element_at_the_end(LinkedList *ll, int new_value){
Node *temporary = calloc(1,sizeof(Node));
temporary->value = new_value;
if (empty_check(ll)){
temporary->next = NULL;
temporary->prev = NULL;
ll->head = temporary;
ll->tail = temporary;
}
else{
temporary->next = NULL;
temporary->prev = ll->tail;
ll->tail->next = temporary;
ll->tail = temporary;
}
}
int eliminate_the_first_element(LinkedList *ll){
Node *temporary = ll->head;
ll->head = ll->head->next;
ll->head->prev = NULL;
int result = temporary->value;
free(temporary);
return result;
}
int eliminate_the_last_element(LinkedList *ll){
Node *temporary = ll->tail;
ll->tail = ll->tail->prev;
ll->tail->next = NULL;
free(temporary);
return temporary->value;
}
void eliminate_the_single_element(LinkedList *ll){
Node *temporary = ll->head;
ll->head = NULL;
ll->tail = NULL;
free(temporary);
}
int add_element_on_another_spot(LinkedList *ll, int new_val){
int position = 0;
scanf("%d", &position);
Node *new_node = calloc(1,sizeof(Node));
new_node->value = new_val;
Node *iterator = ll->head;
for(int i = 0; i < position; ++i){
iterator = iterator->prev;
}
new_node->next = iterator;
new_node->prev = iterator->prev;
iterator->prev->next = new_node;
iterator->prev = new_node;
}
void print_the_linked_list(LinkedList *ll){
Node *curr = ll->head;
while (curr){
printf("%d, ", curr->value);
curr = curr->next;
}
printf("\n");
}
LinkedList * ll;
int main(){
clearing_space_for_LinkedList(ll);
add_element_at_the_beginning(ll, 10);
print_the_linked_list(ll);
}
When i try to run it i get Segmentation fault (core dumped)
Can someone explain why am i getting this message ?
And is my algorithm of creating and using double linked list rightly done ?
Also i am having hard time realizing really how to remove element?
Is the used function above correct for creating space for the list or this:
void clearing_space_for_LinkedList(LinkedList *linkedList) {
linkedList = (LinkedList*)calloc(1, sizeof(LinkedList));
linkedList->head = (Node*)calloc(1, sizeof(Node));
linkedList->tail = (Node*)calloc(1, sizeof(Node));
linkedList->head = NULL;
linkedList->tail = NULL;
}
Is it possible to create double linked list with arrays and if yes, how ?
Will just creating array for value in the typdef structure will work ?

Answer 1

Code has at least these problems:
No NULL check
clearing_space_for_LinkedList(LinkedList *ll) attempts ll->head even when ll == NULL which happens on OP's first call.
Code fails on last node elimination
eliminate_the_first_element() makes no provision for setting ll->tail to NULL should the last node get eliminated.
Similar problem with eliminate_the_last_element().