nested linked list print issue - c

Question

When I running this code and call " List() "function it prints only the last added by user . I want to print from beginning to the end.I hope you will help me about my list function.It prints only the last one.
#include<stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <string.h>
struct seat {
int k_no;
int k_name;
struct seat *next_k, *previous_k;
} *first_k, *temp_k, *last_k;
struct sefer {
char name[20];
int no;
struct sefer *next, *previous;
struct seat *bus;
} *first, *last, *temp;
void list();
void seat_link(int val);
void sefer_search();
int main() {
int val;
printf ("how many names do you want to type ->");
scanf ("%d", &val);
int i;
int j;
for (i = 0; i < val; i++) {
if (first == NULL) {
first = (sefer *)malloc(sizeof(struct sefer));
fflush(stdin);
printf(" %d. name->", i + 1);
scanf("%s", &first->name);
printf(" %d. capacity ->", i + 1);
scanf("%d", &first->no);
first->next = NULL; //2 inci düğüm daha oluşmadığı için null
first->previous = NULL;
last = first; //şimdilik sadece ilk düğüm olduğu için aynı zamanda son oluo
last->bus = NULL;
for (j = 0; j < first->no; j++) {
//KOLTUKLAR OLUŞTURULCAK
if (last->bus == NULL) {
first_k = (seat *)malloc(sizeof(struct seat));
fflush(stdin);
first_k->k_no = j;
first_k->k_name = 1;
first_k->next_k = NULL;
first_k->previous_k = NULL;
last_k = first_k;
last->bus = first_k;
} else {
temp_k = (seat *)malloc(sizeof(struct seat ));
fflush(stdin);
temp_k->k_no = j;
temp_k->k_name = 0;
last_k->next_k = temp_k;
temp_k->previous_k = last_k;
last_k = temp_k;
last_k->last_k = NULL;
}
}
} else if (last == first) {
printf("\n");
last = (sefer *)malloc(sizeof(struct sefer));
fflush(stdin);
printf(" %d. name ->", i + 1);
scanf("%s", &last->name);
printf(" %d. capacitiy ->", i + 1);
scanf("%d", &last->no);
first->next = last;
last>next = NULL;
last->previous = first;
last->bus = NULL;
for (j = 0; j < last->no; j++) {
//KOLTUKLAR OLUŞTURULCAK
if (last->bus == NULL) {
first_k = (seat *)malloc(sizeof(struct seat ));
fflush(stdin);
first_k->k_no = j;
first_k->k_name = 2;
first_k->last_k = NULL;
first_k->previous_k = NULL;
last_k = first_k;
last->bus = first_k;
} else {
temp_k = (seat *)malloc(sizeof(struct seat));
fflush(stdin);
temp_k->k_no = j;
temp_k->k_name = 0;
last_k->next_k = temp_k;
temp_k->previous_k = last_k;
last_k = temp_k;
last_k->last_k = NULL;
}
}
} else { // kayıt eklenmişse diğer düğümler oluşturulcak
printf ("\n");
temp = (sefer *) malloc(sizeof(struct sefer));
fflush(stdin);
printf(" %d. name", i + 1);
scanf("%s", &temp->name);
printf(" %d. capacity->", i + 1);
scanf("%d", &temp->no);
last->next = temp;
temp->previous = last;
last = temp;
last->next = NULL;
last->bus = NULL;
for (j = 0; j < temp->no; j++) {
//KOLTUKLAR OLUŞTURULCAK
if (last->bus == NULL) {
first_k = (seat*)malloc(sizeof(struct seat));
fflush(stdin);
first_k->k_no = j;
first_k->k_name = 3;
first_k->last_k = NULL;
first_k->previous_k = NULL;
last_k = first_k;
last->bus = first_k;
} else {
temp_k = (seat *)malloc(sizeof(struct seat));
fflush(stdin);
temp_k->k_no = j;
temp_k->k_name = 0;
last_k->next_k = temp_k;
temp_k->previous_k = last_k;
last_k = temp_k;
last_k->next_k = NULL;
}
}
}
}
list();
system("PAUSE");
return 0;
}
void sefer_search() { //bağda arama yapar
int searching;
printf("\n\t\t Aranacak Sefer Numarasını Giriniz:");
scanf("%d", &searching);
temp = first;
while (1) {
if (temp->no == searching) {
break;
}
temp = temp->next;
}
}
void seat_link(int val) {
int j;
}
my problem is here actually :
void list() {
temp = first;
while (temp != NULL) {
printf("\t%s --%d \n", temp->name, temp->no);
temp = temp->next;
}
printf ("\n");
last->bus = first_k;
while (last->bus != NULL) {
printf("\t%d --%d \n", last->bus->k_name, last->otobus->k_no);
last->bus = last->bus->next_k;
}
}
Please help me

Answer 1

There are a bunch of problems with your code. Firstly, it won't compile for various reasons. For instance, you sometimes use a struct koltuk without ever defining it. "koltuk" means "seat" in Turkish, so I'm going to assume you meant struct seat in all those cases. Secondly, deg is undefined; I assume you meant val.
There were a few other problems like that which I was able to fix by making plausible guesses. But that leaves the following fundamental problems:
You are using global variables as local variables, for instance temp_k and temp. This makes it well-nigh impossible for a human to analyze your code and understand the control flow.
You have copied code all over the place. You have three separate code blocks to allocate and initialize a sefer depending upon whether it's first in the global linked list, second, or later. Use subroutines!
Your data model seems confused. You have global variables struct *first_k,*temp_k,*last_k; which makes it seem like you have one global linked list of seats for all sefer structs, but the struct seat does not refer back in an obvious way to the sefer that owns it, which implies that each sefer has a separate, private list of seats.
Taking all three problems together, I can't really see where, specifically, you are going wrong. I took a cut at rewriting your code to eliminate these problems. Give it a try to see if it solves your problems:
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <string.h>
typedef struct seat{
int k_no;
int k_name;
struct seat *next_k, *previous_k;
} seat;
typedef struct sefer {
char name[20];
int no;
struct sefer *next,*previous;
struct seat *bus;
} sefer;
void list();
sefer *sefer_search();
void link_sefer(sefer **pp_first, sefer **pp_last, sefer *p_added)
{
p_added->next = p_added->previous = NULL;
if (*pp_first == NULL)
{
*pp_first = *pp_last = p_added;
}
else
{
(*pp_last)->next = p_added;
p_added->previous = *pp_last;
*pp_last = p_added;
}
}
void link_seat(seat **pp_first, seat **pp_last, seat *p_added)
{
p_added->next_k = p_added->previous_k = NULL;
if (*pp_first == NULL)
{
*pp_first = *pp_last = p_added;
}
else
{
(*pp_last)->next_k = p_added;
p_added->previous_k = *pp_last;
*pp_last = p_added;
}
}
sefer *create_and_link_sefer(sefer **pp_first_sefer, sefer **pp_last_sefer, int i)
{
sefer *new_sefer;
seat *p_first_seat = NULL;
seat *p_last_seat = NULL;
int j;
// Allocate and initialize sefer
printf ("\n");
new_sefer = calloc(1, sizeof(struct sefer));
fflush(stdin);
printf (" %d. name->",i+1);
scanf ("%s",&new_sefer->name);
printf (" %d. capacity->",i+1);
scanf ("%d",&new_sefer->no);
new_sefer->bus = NULL;
// Link sefer
link_sefer(pp_first_sefer, pp_last_sefer, new_sefer);
// Allocate seats
for(j=0;j<new_sefer->no;j++){
//KOLTUKLAR OLUŞTURULCAK
seat *p_seat = calloc(1, sizeof(struct seat));
fflush(stdin);
p_seat->k_no=j;
p_seat->k_name = (j != 0 ? 0 : (i+1 > 3 ? 3 : i+1)); // I CAN'T FIGURE OUT WHAT THIS IS SUPPOSED TO BE
link_seat(&p_first_seat, &p_last_seat, p_seat);
}
new_sefer->bus = p_first_seat;
return new_sefer;
}
void sefer_list(sefer *first, sefer *last){
sefer *temp=first;
while (temp !=NULL)
{
seat *seat;
printf("\t%s --%d \n", temp->name,temp->no);
for (seat = temp->bus; seat != NULL; seat = seat->next_k)
{
printf("\t\t%d --%d \n",seat->k_name, seat->k_no);
}
printf ("\n");
temp=temp->next;
}
}
sefer *sefer_search(sefer *first, sefer *last){ //bağda arama yapar
int arama;
sefer *temp;
printf ("\n\t\t Aranacak Sefer Numarasını Giriniz:");
scanf ("%d",&arama);
temp=first;
while (temp != NULL){
if (temp->no==arama){
break;
}
temp=temp->next;
}
return temp;
}
sefer *first = NULL;
sefer *last = NULL;
int main( )
{
int val;
int i;
printf ("how many names do you want to type ->");
scanf ("%d",&val);
for(i=0;i<val;i++){
create_and_link_sefer(&first, &last, i);
}
sefer_list(first, last);
system("PAUSE");
return 0;
}
It seems to work, but since I don't know what you are trying to do, it might not be working as you want.

Answer 2

Judging by the logic, that means that temp really isn't going anywhere. My guess is that when you set those pointers *first, *last, *temp; in the first few lines of main, you don't really point first to NULL, causing it to skip the first if statement. Pointers don't point to NULL by default, they point to whatever was at that memory location beforehand. In this case, garbage. Try adding first=NULL; prior to your first if-statement.