One of my functions is accidentally deleting elements from list - c

Question

I am trying to make a "library" where there are alphabetically-sorted catalogs and each of them has books also in alphabetical order. As part of deletebook function(not included because it's not there yet), I wrote function that finds catalog of the book. The function works, but it deletes books in the process( I think) which is not good. How to change it so it doesn't delete them?
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
struct book
{
char *title;
int number;
char *country;
struct book* new;
};
struct catalog
{
char *name;
struct catalog* next;
struct book* firstbook;
};
void printList(struct catalog *head)
{
struct catalog *temp = head;
while(temp != NULL)
{
struct book* book = temp->firstbook;
if(book == NULL)
{
printf("%s\n", temp->name);
}
while(book != NULL)
{
printf("%s ", temp->name);
printf("%s ", book->title);
printf("%d ", book->number);
printf("%s\n", book->country);
book = book->new;
}
temp = temp->next;
}
}
struct catalog *newcatalog(char *new_name)
{
struct catalog* new_node = (struct catalog*) malloc(sizeof(struct catalog));
new_node->name = malloc(strlen(new_name)+1);
strcpy(new_node->name, new_name);
new_node->next = NULL;
new_node->firstbook = NULL;
return new_node;
}
struct book *newbook(char *booktitle, int number, char *country)
{
struct book* newbook = (struct book*) malloc(sizeof(struct book));
newbook->title = malloc(strlen(booktitle)+1);
newbook->country = malloc(strlen(country)+1);
strcpy(newbook->title, booktitle);
strcpy(newbook->country, country);
newbook->number = number;
newbook->new = NULL;
return newbook;
}
struct catalog *findcatalog(struct catalog** head, char *catalogname)
{
struct catalog* current;
current = *head;
while(current != NULL)
{
if(!strcmp(current->name,catalogname))
{
return current;
}
current = current->next;
}
return NULL;
}
struct catalog *findbookcatalog(struct catalog** head, int number) //function that deletes a book when used
{
struct catalog* current;
current = *head;
while(current != NULL)
{
while(current->firstbook != NULL)
{
if(current->firstbook->number == number)
{
return current;
}
current->firstbook = current->firstbook->new;
}
current = current->next;
}
return NULL;
}
struct book *findbook(struct catalog** head, int number)
{
struct catalog* current = findbookcatalog(head, number);
struct book* booklocation;
while(current->firstbook != NULL)
{
booklocation = current->firstbook;
if(current->firstbook->number == number)
{
return booklocation;
}
current->firstbook = current->firstbook->new;
}
return NULL;
}
void sortedBookInsert(struct catalog** head, char *catalogname, char *booktitle, int number, char *country)
{
struct catalog* searched;
struct book* pom;
struct book* ksiazka = newbook(booktitle, number, country);
searched = findcatalog(head, catalogname);
if(searched->firstbook == NULL || strcmp(searched->firstbook->title, ksiazka->title)>0)
{
ksiazka->new =searched->firstbook;
searched->firstbook = ksiazka;
}
else
{ pom = searched->firstbook;
while(pom->new!= NULL && strcmp(searched->firstbook->title, ksiazka->title)< 0)
{
pom = pom->new;
}
ksiazka->new = pom->new;
pom->new = ksiazka;
}
}
void sortedInsert(struct catalog** head,char *name)
{
struct catalog* current;
struct catalog* new_node = newcatalog(name);
if(new_node == NULL)
{
return;
}
if (*head == NULL || strcmp((*head)->name, new_node->name) > 0)
{
new_node->next = *head;
*head = new_node;
}
else
{
current = *head;
while (current->next!=NULL && strcmp(current->next->name, new_node->name) < 0)
{
current = current->next;
}
new_node->next = current->next;
current->next = new_node;
}
}
int main()
{
struct catalog* head = NULL;
sortedInsert(&head, "Kappa");
sortedInsert(&head, "Pxntry");
sortedInsert(&head, "Sdafscx");
sortedInsert(&head, "Saxzxc");
sortedInsert(&head, "Zsdas");
sortedInsert(&head, "Zzzzzzzz");
sortedInsert(&head, "Country");
sortedBookInsert(&head, "Country", "PKP", 11111, "Germany");
sortedBookInsert(&head, "Country", "Polacy", 11112, "Italy");
sortedBookInsert(&head, "Country", "Bus", 11234, "France");
sortedBookInsert(&head, "Country", "Poltics", 14111, "Russia");
printList(head);
findbookcatalog(&head, 11112); // this will "eat" "Bus" and "PKP", so books that appear before Polacy
printf("\n");
printList(head);
return 0;
}
It should print my nested lists two times, two times the same, but it deletes all books that are before the searched book.
Result:
Country Bus 11234 France
Country PKP 11111 Germany
Country Polacy 11112 Italy
Country Poltics 14111 Russia
Kappa
Pxntry
Saxzxc
Sdafscx
Zsdas
Zzzzzzzz
Country Polacy 11112 Italy
Country Poltics 14111 Russia
Kappa
Pxntry
Saxzxc
Sdafscx
Zsdas
Zzzzzzzz

Answer 1

This code is removing books from a list:
current->firstbook = current->firstbook->new;
You probably meant to use something like this:
current_book = current->firstbook;
while (current_book) {
if (current_book->number == number) {
return current_book;
}
current_book = current_book->new;
}
I changed this function which fixes your current problem:
struct catalog *findbookcatalog(struct catalog** head, int number) //function that deletes a book when used
{
struct catalog* current;
current = *head;
struct book *current_book;
while(current != NULL)
{
current_book = current->firstbook;
while(current_book != NULL)
{
if(current_book->number == number)
{
return current;
}
current_book = current_book->new;
}
current = current->next;
}
return NULL;
}
I also changed this function. It has the same problem, you just haven't tested it yet.
struct book *findbook(struct catalog** head, int number)
{
struct catalog* current = findbookcatalog(head, number);
struct book* booklocation;
if (current != NULL) {
booklocation = current->firstbook;
while(booklocation != NULL)
{
if(booklocation->number == number)
{
return booklocation;
}
booklocation = booklocation->new;
}
}
return NULL;
}