Overview

This is an implementation of a singly linked list in C. A linked list is a linear data structure where elements are stored in a sequence, but each element is linked to the next element using a pointer. This implementation uses a single linked list, meaning each node has a pointer to the next node, but not to the previous node.

Interface

The LinkedList struct represents the linked list. It contains a pointer to the head node of the list.

typedef struct node {
  int value;
  struct node* next;
} Node;

typedef struct linked_list {
  Node* head;
} LinkedList;

Basic Operations

• init(LinkedList* list): Initializes the linked list by setting the head node to NULL.
• append(LinkedList* list, int value): Appends a new node with the given value to the end of the linked list.
• get(LinkedList* list, int index): Returns the value of the node at the given index. Returns -1 if the index is out of bounds.
• set(LinkedList* list, int index, int value): Sets the value of the node at the given index to the given value.
• getSize(LinkedList* list): Returns the number of nodes in the linked list.
• cleanup(LinkedList* list): Frees the memory used by the linked list.

Usage

Here is an example program that uses the linked list implementation to store and print some numbers:

#include <stdio.h>
#include "linkedlist.h"

int main() {
  LinkedList list;
  init(&list);

  // add some numbers to the list
  append(&list, 42);
  append(&list, 17);
  append(&list, 56);
  append(&list, 23);

  // print the numbers in the list
  int size = getSize(&list);
  for (int i = 0; i < size; i++) {
    int value = get(&list, i);
    printf("%d ", value);
  }
  printf("\n");

  // change the second number in the list
  set(&list, 1, 99);

  // print the numbers in the list again
  size = getSize(&list);
  for (int i = 0; i < size; i++) {
    int value = get(&list, i);
    printf("%d ", value);
  }
  printf("\n");

  cleanup(&list);

  return 0;