Kolokwium_Lista

// Implementacja Listy
#include <stdio.h>
#include <stdlib.h>

struct list_node{
    int data;
    struct list_node *next;
} *list_pointer;

struct list_node *create_list(int data)
{
    struct list_node *first = (struct list_node*)malloc(sizeof(struct list_node));
    if(first){
        first->data = data;
        first->next = NULL;
    }
    return first;
}

struct list_node *add_in_front(struct list_node *list_pointer, struct list_node *new_node)
{
    new_node->next = list_pointer;
    return new_node;
}

struct list_node *find_spot(struct list_node *list_pointer, int data)
{
    struct list_node *previous = NULL;
    while(list_pointer && list_pointer->data < data){
        previous = list_pointer;
        list_pointer = list_pointer->next;
    }
    return previous;
}

void add_in_middle_or_at_back(struct list_node *node, struct list_node *new_node)
{
    new_node->next = node->next;
    node->next = new_node;
}

struct list_node *add_node(struct list_node *list_pointer, int data)
{
    struct list_node *new_node = (struct list_node*)malloc(sizeof(struct list_node));
    if(list_pointer && new_node){
        new_node->data = data;
        if(list_pointer->data >= data){
            return add_in_front(list_pointer, new_node);
            }
        else{
            struct list_node *tmp = find_spot(list_pointer, data);
            add_in_middle_or_at_back(tmp, new_node);
        }
    }
    return list_pointer;
}

struct list_node *delete_at_front(struct list_node *list_pointer)
{
    struct list_node *next = list_pointer->next;
    free(list_pointer);
    return next;
}

struct list_node *find_previous_node(struct list_node *list_pointer, int data)
{
    struct list_node *previous = NULL;
    while(list_pointer && list_pointer->data != data){
        previous = list_pointer;
        list_pointer = list_pointer->next;
    }
    return previous;
}

void delete_in_middle_or_at_back(struct list_node *previous)
{
    struct list_node *node = previous->next;
    if(node){
        previous->next = node->next;
        free(node);
    }
}

struct list_node *delete_node(struct list_node *list_pointer, int data)
{
    if(list_pointer){
        if(list_pointer->data == data){
            return delete_at_front(list_pointer);
        }
        else{
            struct list_node *tmp = find_previous_node(list_pointer, data);
            delete_in_middle_or_at_back(tmp);
        }
    }
    return list_pointer;
}

void print_list(struct list_node *list_pointer)
{
    while(list_pointer){
        printf("%d ", list_pointer->data);
        list_pointer = list_pointer->next;
    }
    printf("\n");
}

void remove_list(struct list_node **list_pointer)
{
    while(*list_pointer){
        struct list_node *tmp_next = (*list_pointer)->next;
        free(*list_pointer);
        *list_pointer = tmp_next;
    }
}

int main(void)
{
    list_pointer = create_list(3);
    list_pointer = add_node(list_pointer, 9);
    list_pointer = add_node(list_pointer, 2);
    list_pointer = add_node(list_pointer, 5);
    list_pointer = delete_node(list_pointer, 9);

    print_list(list_pointer);
    remove_list(&list_pointer);

    return 0;
}