ll.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef struct list List;
typedef struct node Node;

struct node {
  int data;
  Node* next;
};

struct list {
  Node* head;
};

List* initList(){
  List* ll = (List*)malloc(sizeof(List));
  if(!ll) return NULL;

  ll->head = NULL;
  return ll;
}

void destroyList(List* ll){
  Node* curr = ll->head;

  while(curr != NULL){
    Node* tmp = curr->next;
    free(curr);
    curr = curr->next;
  }

  free(ll);
}

bool addNode(int data, List* ll){
  Node* newNode = (Node*)malloc(sizeof(Node));
  if(!newNode) return false;

  newNode->data = data;
  newNode->next = NULL;

  if(!ll->head){
    ll->head = newNode;
  }
  else{
    newNode->next = ll->head;
    ll->head = newNode;
  }

  return true;
}

bool deleteNode(int data, List* ll){
  Node* prev = NULL;
  Node* curr = ll->head;
  bool found = false;

  while(curr && curr->data != data){
    prev = curr;
    curr = curr->next;
  }

  if(curr){
    if(curr->data == data)
      found = true;
  }
  else
    return found;

  if(prev){
    prev->next = curr->next;
  }
  else{
    ll->head = curr->next;
  }
  
  free(curr);
  return found;
}

void traverseList(List* ll){
  printf("%s\n", "Traversing: ");
  Node* curr = ll->head;
  while(curr != NULL){
    printf("%d\n", curr->data);
    curr = curr->next;
  }
}

int main(){
  List* ll = initList();
  
  addNode(55, ll);
  addNode(65, ll);
  traverseList(ll);
  
  deleteNode(65, ll);
  traverseList(ll);

  destroyList(ll);
}