linkedList.c

//code to create linked list by adding at head and tail and displaying the data ,
// deleting the node and searching in linked list , and also reversing the linked list
// by iterating method and recursive method
#include <bits/stdc++.h>
using namespace std;

class node
{
public:
    int data;
    node *next;

    node(int val)
    {
        data = val;
        next = NULL;
    }
};

void insertAtHead(node *&head, int val)
{
    node *n = new node(val);
    n->next = head;
    head = n;
}

void insertAtTail(node *&head, int val)
{
    node *n = new node(val);

    if (head == NULL)
    {
        head = n;
        return;
    }

    node *temp = head;
    while (temp->next != NULL)
    {
        temp = temp->next;
    }
    temp->next = n;
}

void display(node *head)
{
    node *temp = head;
    while (temp != NULL)
    {
        cout << temp->data << "->";
        temp = temp->next;
    }
    cout << "NULL" << endl;
}

bool search(node *head, int key)
{
    node *temp = head;
    while (temp != NULL)
    {
        if (temp->data == key)
        {
            return true;
        }
        temp = temp->next;
    }
    return false;
}

void deleteAtHead(node *&head)
{
    node *todelete = head;
    head = head->next;
    delete todelete;
}

node *reverse(node *&head)
{
    node *prevptr = NULL;
    node *currptr = head;
    node *nextptr;
    while (currptr != NULL)
    {
        nextptr = currptr->next;
        currptr->next = prevptr;

        prevptr = currptr;
        currptr = nextptr;
    }
    return prevptr;
}

node *reverseRecursive(node *&head)
{
    if (head == NULL || head->next == NULL)
    {
        return head;
    }
    node *newhead = reverseRecursive(head->next);
    head->next->next = head;
    head->next = NULL;
    return newhead;
}

void deletion(node *&head, int val)
{
    if (head == NULL)
    {
        return;
    }
    if (head->next == NULL)
    {
        deleteAtHead(head);
        return;
    }
    node *temp = head;
    while (temp->next->data != val)
    {
        temp = temp->next;
    }
    node *todelete = temp->next;
    temp->next = temp->next->next;
    delete todelete;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    node *head = NULL;
    insertAtTail(head, 1);
    insertAtTail(head, 2);
    insertAtTail(head, 3);
    insertAtTail(head, 4);
    display(head);
    cout << search(head, 3) << endl;
    deletion(head, 3);
    deleteAtHead(head);
    display(head);
    node *newhead = reverseRecursive(head);
    display(newhead);
}