Resources

Read or watch:

Google
Youtube

Learning Objectives

At the end of this project, you are expected to be able to explain to anyone, without the help of Google:

General

How to use linked lists
Start to look for the right source of information without too much help

Requirements

General

Allowed editors: vi, vim, emacs
All your files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89
All your files should end with a new line
A README.md file, at the root of the folder of the project is mandatory
Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
You are not allowed to use global variables
No more than 5 functions per file
The only C standard library functions allowed are malloc, free and exit. Any use of functions like printf, puts, calloc, realloc etc… is forbidden
You are allowed to use _putchar
You don’t have to push _putchar.c, we will use our file. If you do it won’t be taken into account
In the following examples, the main.c files are shown as examples. You can use them to test your functions, but you don’t have to push them to your repo (if you do we won’t take them into account). We will use our own main.c files at compilation. Our main.c files might be different from the one shown in the examples
The prototypes of all your functions and the prototype of the function _putchar should be included in your header file called lists.h
Don’t forget to push your header file
All your header files should be include guarded

More Info

Please use this data structure for this project:

/**
 * struct listint_s - singly linked list
 * @n: integer
 * @next: points to the next node
 *
 * Description: singly linked list node structure
 *
 */
typedef struct listint_s
{
    int n;
    struct listint_s *next;
} listint_t;

Tasks

0. Print list

Write a function that prints all the elements of a listint_t list.

Prototype: size_t print_listint(const listint_t *h);
Return: the number of nodes
Format: see example
You are allowed to use printf

julien@ubuntu:~/0x13. More singly linked lists$ cat 0-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *new;
    listint_t hello = {8, NULL};
    size_t n;

    head = &hello;
    new = malloc(sizeof(listint_t));
    if (new == NULL)
    {
        printf("Error\n");
        return (1);
    }
    new->n = 9;
    new->next = head;
    head = new;
    n = print_listint(head);
    printf("-> %lu elements\n", n);
    free(new);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 0-main.c 0-print_listint.c -o a
julien@ubuntu:~/0x13. More singly linked lists$ ./a
9
8
-> 2 elements
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 0-print_listint.c

1. List length

Write a function that returns the number of elements in a linked listint_t list.

Prototype: size_t listint_len(const listint_t *h);

julien@ubuntu:~/0x13. More singly linked lists$ cat 1-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *new;
    listint_t hello = {8, NULL};
    size_t n;

    head = &hello;
    new = malloc(sizeof(listint_t));
    if (new == NULL)
    {
        printf("Error\n");
        return (1);
    }
    new->n = 9;
    new->next = head;
    head = new;
    n = listint_len(head);
    printf("-> %lu elements\n", n);
    free(new);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 1-main.c 1-listint_len.c -o b
julien@ubuntu:~/0x13. More singly linked lists$ ./b
-> 2 elements
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 1-listint_len.c

2. Add node

Write a function that adds a new node at the beginning of a listint_t list.

Prototype: listint_t *add_nodeint(listint_t **head, const int n);
Return: the address of the new element, or NULL if it failed

julien@ubuntu:~/0x13. More singly linked lists$ cat 2-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint(&head, 0);
    add_nodeint(&head, 1);
    add_nodeint(&head, 2);
    add_nodeint(&head, 3);
    add_nodeint(&head, 4);
    add_nodeint(&head, 98);
    add_nodeint(&head, 402);
    add_nodeint(&head, 1024);
    print_listint(head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 2-main.c 2-add_nodeint.c 0-print_listint.c -o c
julien@ubuntu:~/0x13. More singly linked lists$ ./c
1024
402
98
4
3
2
1
0
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 2-add_nodeint.c

3. Add node at the end

Write a function that adds a new node at the end of a listint_t list.

Prototype: listint_t *add_nodeint_end(listint_t **head, const int n);
Return: the address of the new element, or NULL if it failed

julien@ubuntu:~/0x13. More singly linked lists$ cat 3-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 3-main.c 3-add_nodeint_end.c 0-print_listint.c -o d
julien@ubuntu:~/0x13. More singly linked lists$ ./d
0
1
2
3
4
98
402
1024
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 3-add_nodeint_end.c

4. Free list

Write a function that frees a listint_t list.

Prototype: void free_listint(listint_t *head);

julien@ubuntu:~/0x13. More singly linked lists$ cat 4-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    free_listint(head);
    head = NULL;
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 4-main.c 3-add_nodeint_end.c 0-print_listint.c 4-free_listint.c -o e
julien@ubuntu:~/0x13. More singly linked lists$ valgrind ./e
==3643== Memcheck, a memory error detector
==3643== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==3643== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==3643== Command: ./e
==3643==
0
1
2
3
4
98
402
1024
==3643==
==3643== HEAP SUMMARY:
==3643==     in use at exit: 0 bytes in 0 blocks
==3643==   total heap usage: 9 allocs, 9 frees, 1,152 bytes allocated
==3643==
==3643== All heap blocks were freed -- no leaks are possible
==3643==
==3643== For counts of detected and suppressed errors, rerun with: -v
==3643== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 4-free_listint.c

5. Free

Write a function that frees a listint_t list.

Prototype: void free_listint2(listint_t **head);
The function sets the head to NULL

julien@ubuntu:~/0x13. More singly linked lists$ cat 5-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    free_listint2(&head);
    printf("%p\n", (void *)head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 5-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c -o f
julien@ubuntu:~/0x13. More singly linked lists$ valgrind ./f
==3843== Memcheck, a memory error detector
==3843== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==3843== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==3843== Command: ./f
==3843==
0
1
2
3
4
98
402
1024
(nil)
==3843==
==3843== HEAP SUMMARY:
==3843==     in use at exit: 0 bytes in 0 blocks
==3843==   total heap usage: 9 allocs, 9 frees, 1,152 bytes allocated
==3843==
==3843== All heap blocks were freed -- no leaks are possible
==3843==
==3843== For counts of detected and suppressed errors, rerun with: -v
==3843== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 5-free_listint2.c

6. Pop

Write a function that deletes the head node of a listint_t linked list, and returns the head node’s data (n).

Prototype: int pop_listint(listint_t **head);
if the linked list is empty return 0

julien@ubuntu:~/0x13. More singly linked lists$ cat 6-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    int n;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    n = pop_listint(&head);
    printf("- %d\n", n);
    print_listint(head);
    n = pop_listint(&head);
    printf("- %d\n", n);
    print_listint(head);
    free_listint2(&head);
    printf("%p\n", (void *)head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 6-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c 6-pop_listint.c -o g
julien@ubuntu:~/0x13. More singly linked lists$ valgrind ./g
==4369== Memcheck, a memory error detector
==4369== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==4369== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==4369== Command: ./g
==4369==
0
1
2
3
4
98
402
1024
- 0
1
2
3
4
98
402
1024
- 1
2
3
4
98
402
1024
(nil)
==4369==
==4369== HEAP SUMMARY:
==4369==     in use at exit: 0 bytes in 0 blocks
==4369==   total heap usage: 9 allocs, 9 frees, 1,152 bytes allocated
==4369==
==4369== All heap blocks were freed -- no leaks are possible
==4369==
==4369== For counts of detected and suppressed errors, rerun with: -v
==4369== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 6-pop_listint.c

7. Get node at index

Write a function that returns the nth node of a listint_t linked list.

Prototype: listint_t *get_nodeint_at_index(listint_t *head, unsigned int index);
where index is the index of the node, starting at 0
if the node does not exist, return NULL

julien@ubuntu:~/0x13. More singly linked lists$ cat 7-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *node;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    node = get_nodeint_at_index(head, 5);
    printf("%d\n", node->n);
    print_listint(head);
    free_listint2(&head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 7-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c 7-get_nodeint.c -o h
julien@ubuntu:~/0x13. More singly linked lists$ ./h
0
1
2
3
4
98
402
1024
98
0
1
2
3
4
98
402
1024
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 7-get_nodeint.c

8. Sum list

Write a function that returns the sum of all the data (n) of a listint_t linked list.

Prototype: int sum_listint(listint_t *head);
if the list is empty, return 0

julien@ubuntu:~/0x13. More singly linked lists$ cat 8-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    int sum;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    sum = sum_listint(head);
    printf("sum = %d\n", sum);
    free_listint2(&head);
    return (0);
}
julien@ubuntu:~/c0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 8-main.c 3-add_nodeint_end.c 5-free_listint2.c 8-sum_listint.c -o i
julien@ubuntu:~/0x13. More singly linked lists$ ./i
sum = 1534
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 8-sum_listint.c

9. Insert

Write a function that inserts a new node at a given position.

Prototype: listint_t *insert_nodeint_at_index(listint_t **head, unsigned int idx, int n);
where idx is the index of the list where the new node should be added. Index starts at 0
Returns: the address of the new node, or NULL if it failed
if it is not possible to add the new node at index idx, do not add the new node and return NULL

julien@ubuntu:~/0x13. More singly linked lists$ cat 9-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    printf("-----------------\n");
    insert_nodeint_at_index(&head, 5, 4096);
    print_listint(head);
    free_listint2(&head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 9-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c 9-insert_nodeint.c -o j
julien@ubuntu:~/0x13. More singly linked lists$ ./j
0
1
2
3
4
98
402
1024
-----------------
0
1
2
3
4
4096
98
402
1024
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 9-insert_nodeint.c

10. Delete at index

Write a function that deletes the node at index index of a listint_t linked list.

Prototype: int delete_nodeint_at_index(listint_t **head, unsigned int index);
where index is the index of the node that should be deleted. Index starts at 0
Returns: 1 if it succeeded, -1 if it failed

julien@ubuntu:~/0x13. More singly linked lists$ cat 10-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 5);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    printf("-----------------\n");
    delete_nodeint_at_index(&head, 0);
    print_listint(head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 10-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c 10-delete_nodeint.c -o k
julien@ubuntu:~/0x13. More singly linked lists$ valgrind ./k
==5571== Memcheck, a memory error detector
==5571== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==5571== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==5571== Command: ./k
==5571==
0
1
2
3
4
98
402
1024
-----------------
0
1
2
3
4
402
1024
-----------------
1
2
3
4
402
1024
-----------------
2
3
4
402
1024
-----------------
3
4
402
1024
-----------------
4
402
1024
-----------------
402
1024
-----------------
1024
-----------------
-----------------
-----------------
-----------------
-----------------
-----------------
-----------------
-----------------
-----------------
-----------------
==5571==
==5571== HEAP SUMMARY:
==5571==     in use at exit: 0 bytes in 0 blocks
==5571==   total heap usage: 9 allocs, 9 frees, 1,152 bytes allocated
==5571==
==5571== All heap blocks were freed -- no leaks are possible
==5571==
==5571== For counts of detected and suppressed errors, rerun with: -v
==5571== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 10-delete_nodeint.c

11. Reverse list

Write a function that reverses a listint_t linked list.

Prototype: listint_t *reverse_listint(listint_t **head);
Returns: a pointer to the first node of the reversed list
You are not allowed to use more than 1 loop.
You are not allowed to use malloc, free or arrays
You can only declare a maximum of two variables in your function

julien@ubuntu:~/0x13. More singly linked lists$ cat 100-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;

    head = NULL;
    add_nodeint_end(&head, 0);
    add_nodeint_end(&head, 1);
    add_nodeint_end(&head, 2);
    add_nodeint_end(&head, 3);
    add_nodeint_end(&head, 4);
    add_nodeint_end(&head, 98);
    add_nodeint_end(&head, 402);
    add_nodeint_end(&head, 1024);
    print_listint(head);
    reverse_listint(&head);
    print_listint(head);
    free_listint2(&head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 100-main.c 3-add_nodeint_end.c 0-print_listint.c 5-free_listint2.c 100-reverse_listint.c -o l
julien@ubuntu:~/0x13. More singly linked lists$ valgrind ./l
==3117== Memcheck, a memory error detector
==3117== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==3117== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==3117== Command: ./l
==3117==
0
1
2
3
4
98
402
1024
1024
402
98
4
3
2
1
0
==3117==
==3117== HEAP SUMMARY:
==3117==     in use at exit: 0 bytes in 0 blocks
==3117==   total heap usage: 9 allocs, 9 frees, 1,152 bytes allocated
==3117==
==3117== All heap blocks were freed -- no leaks are possible
==3117==
==3117== For counts of detected and suppressed errors, rerun with: -v
==3117== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 100-reverse_listint.c

12. Print (safe version)

Write a function that prints a listint_t linked list.

Prototype: size_t print_listint_safe(const listint_t *head);
Returns: the number of nodes in the list
This function can print lists with a loop
You should go through the list only once
If the function fails, exit the program with status 98
Output format: see example

julien@ubuntu:~/0x13. More singly linked lists$ cat 101-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *head2;
    listint_t *node;

    head2 = NULL;
    add_nodeint(&head2, 0);
    add_nodeint(&head2, 1);
    add_nodeint(&head2, 2);
    add_nodeint(&head2, 3);
    add_nodeint(&head2, 4);
    add_nodeint(&head2, 98);
    add_nodeint(&head2, 402);
    add_nodeint(&head2, 1024);
    print_listint_safe(head2);
    head = NULL;
    node = add_nodeint(&head, 0);
    add_nodeint(&head, 1);
    add_nodeint(&head, 2);
    add_nodeint(&head, 3);
    add_nodeint(&head, 4);
    node->next = add_nodeint(&head, 98);
    add_nodeint(&head, 402);
    add_nodeint(&head, 1024);
    print_listint_safe(head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 101-main.c 2-add_nodeint.c 101-print_listint_safe.c -o m
julien@ubuntu:~/0x13. More singly linked lists$ ./m
[0x1b500f0] 1024
[0x1b500d0] 402
[0x1b500b0] 98
[0x1b50090] 4
[0x1b50070] 3
[0x1b50050] 2
[0x1b50030] 1
[0x1b50010] 0
[0x1b50600] 1024
[0x1b505e0] 402
[0x1b505c0] 98
[0x1b505a0] 4
[0x1b50580] 3
[0x1b50560] 2
[0x1b50540] 1
[0x1b50110] 0
-> [0x1b505c0] 98
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 101-print_listint_safe.c

13. Free (safe version)

Write a function that frees a listint_t list.

Prototype: size_t free_listint_safe(listint_t **h);
This function can free lists with a loop
You should go though the list only once
Returns: the size of the list that was free’d
The function sets the head to NULL

julien@ubuntu:~/0x13. More singly linked lists$ cat 102-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *head2;
    listint_t *node;

    head2 = NULL;
    add_nodeint(&head2, 0);
    add_nodeint(&head2, 1);
    add_nodeint(&head2, 2);
    add_nodeint(&head2, 3);
    add_nodeint(&head2, 4);
    add_nodeint(&head2, 98);
    add_nodeint(&head2, 402);
    add_nodeint(&head2, 1024);
    print_listint_safe(head2);
    head = NULL;
    node = add_nodeint(&head, 0);
    add_nodeint(&head, 1);
    add_nodeint(&head, 2);
    add_nodeint(&head, 3);
    add_nodeint(&head, 4);
    node->next = add_nodeint(&head, 98);
    add_nodeint(&head, 402);
    add_nodeint(&head, 1024);
    print_listint_safe(head);
    free_listint_safe(&head2);
    free_listint_safe(&head);
    printf("%p, %p\n", (void *)head2, (void *)head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 102-main.c 2-add_nodeint.c 101-print_listint_safe.c 102-free_listint_safe.c -o n
julien@ubuntu:~/0x13. More singly linked lists$ ./n
[0x11260f0] 1024
[0x11260d0] 402
[0x11260b0] 98
[0x1126090] 4
[0x1126070] 3
[0x1126050] 2
[0x1126030] 1
[0x1126010] 0
[0x1126600] 1024
[0x11265e0] 402
[0x11265c0] 98
[0x11265a0] 4
[0x1126580] 3
[0x1126560] 2
[0x1126540] 1
[0x1126110] 0
-> [0x11265c0] 98
(nil), (nil)
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 102-free_listint_safe.c

14. Find the loop

Write a function that finds the loop in a linked list.

Prototype: listint_t *find_listint_loop(listint_t *head);
Returns: The address of the node where the loop starts, or NULL if there is no loop
You are not allowed to use malloc, free or arrays
You can only declare a maximum of two variables in your function

julien@ubuntu:~/0x13. More singly linked lists$ cat 103-main.c
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "lists.h"

/**
 * main - check the code
 *
 * Return: Always 0.
 */
int main(void)
{
    listint_t *head;
    listint_t *head2;
    listint_t *node;

    head2 = NULL;
    add_nodeint(&head2, 0);
    add_nodeint(&head2, 1);
    add_nodeint(&head2, 2);
    add_nodeint(&head2, 3);
    add_nodeint(&head2, 4);
    add_nodeint(&head2, 98);
    add_nodeint(&head2, 402);
    add_nodeint(&head2, 1024);
    print_listint_safe(head2);
    node = find_listint_loop(head2);
    if (node != NULL)
    {
        printf("Loop starts at [%p] %d\n", (void *)node, node->n);
    }
    free_listint_safe(&head2);
    head = NULL;
    node = add_nodeint(&head, 0);
    add_nodeint(&head, 1);
    add_nodeint(&head, 2);
    add_nodeint(&head, 3);
    add_nodeint(&head, 4);
    add_nodeint(&head, 5);
    add_nodeint(&head, 6);
    node->next = add_nodeint(&head, 7);
    add_nodeint(&head, 98);
    add_nodeint(&head, 402);
    add_nodeint(&head, 1024);
    print_listint_safe(head);
    node = find_listint_loop(head);
    if (node != NULL)
    {
        printf("Loop starts at [%p] %d\n", (void *)node, node->n);
    }
    free_listint_safe(&head);
    return (0);
}
julien@ubuntu:~/0x13. More singly linked lists$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 103-main.c 2-add_nodeint.c 101-print_listint_safe.c 102-free_listint_safe.c 103-find_loop.c -o o
julien@ubuntu:~/0x13. More singly linked lists$ ./o
[0x13700f0] 1024
[0x13700d0] 402
[0x13700b0] 98
[0x1370090] 4
[0x1370070] 3
[0x1370050] 2
[0x1370030] 1
[0x1370010] 0
[0x1370560] 1024
[0x1370540] 402
[0x1370010] 98
[0x1370030] 7
[0x1370050] 6
[0x1370070] 5
[0x1370090] 4
[0x13700b0] 3
[0x13700d0] 2
[0x13700f0] 1
[0x1370110] 0
-> [0x1370030] 7
Loop starts at [0x1370030] 7
julien@ubuntu:~/0x13. More singly linked lists$

Repo:

GitHub repository: alx-low_level_programming
Directory: 0x13-more_singly_linked_lists
File: 103-find_loop.c

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README.md

README.md

Resources

Learning Objectives

General

Requirements

General

More Info

Tasks

0. Print list

1. List length

2. Add node

3. Add node at the end

4. Free list

5. Free

6. Pop

7. Get node at index

8. Sum list

9. Insert

10. Delete at index

11. Reverse list

12. Print (safe version)

13. Free (safe version)

14. Find the loop

Files

README.md

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README.md

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Resources

Learning Objectives

General

Requirements

General

More Info

Tasks

0. Print list

1. List length

2. Add node

3. Add node at the end

4. Free list

5. Free

6. Pop

7. Get node at index

8. Sum list

9. Insert

10. Delete at index

11. Reverse list

12. Print (safe version)

13. Free (safe version)

14. Find the loop