linkedlist.c

typedef struct Node
{
    int val;
    struct Node * next;
} Node;

void insert(Node** head, Node* toIns)
{
    toIns->next = *head;
    *head = toIns;
}

int length(Node* head)
{
    int count = 0;
    while (head)
    {
        ++count;
        head = head->next;
    }
    return count;
}

int contains(Node* head, int data)
{
    while (head)
    {
        if (head->val == data)
        {
            return 1;
        }
        head = head->next;
    }
    return 0;
}

void delete(Node** head, Node* toDel)
{
    Node* temp = *head;
    if (toDel == *head)
    {
        *head = (*head)->next;
        free(toDel);
    } else
    {
        while (temp)
        {
            if (temp->next == toDel)
            {
                temp->next = toDel->next;
                free(toDel);
            }
            temp = temp->next;
        }
    }
}

int count(Node* head, int data)
{
    int count = 0;
    while (head)
    {
        if (head->val == data)
        {
            ++count;
        }
        head = head->next;
    }
    return count;
}

Node* reverse(Node* head)
{
   Node* current = NULL;
   Node* previous = NULL;
   while (head != NULL)
   {
      current = head;
      head = head->next;
      current->next = previous;
      previous = current;
   }
   // This now holds the head element
   return previous;
}