Linked_List

#include<bits/stdc++.h>
using namespace std;

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

class linkedList{
    public :
     node *head;

    linkedList(){
        head = NULL;
    }

    node* createNewNode(int value){
        node *newNode = new node;
        newNode -> data = value;
        newNode -> next = NULL;
        return newNode;
    }

    void insertAtHead(int value){
        node *a = createNewNode(value);

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

        else{
            a -> next = head;
            head = a;
        }
    }

    void insertAtAnyPos(int index , int value){
        if(index == 0){
            insertAtHead(value);
            return;
        }

        node *a = head;
        int cur_index=0;
        while(cur_index != index-1){
            a = a->next;
            cur_index++;
        }

        node *newNode = createNewNode(value);
        newNode ->next = a -> next;
        a -> next = newNode;
    }

    void inserAfterValue(int target , int value){
        node *a = head;
        int c = 0;
        while(a != NULL){
            if(a->data == target){
                break;
            }
            a = a->next;
            node *newNode = createNewNode(value);
            newNode -> next = a -> next;
            a -> next = newNode;
        }
        if( a == NULL){
            cout << "This value not Found!" << endl;
        }
    }

    void deleteFromHead(){
        if(head == NULL){
            return;
        }
        node *a = head;
        head = a -> next;
    }

    void deleteFromIndex(int index){
        if(index == 0){
            deleteFromHead();
            return;
        }

        int cur_index = 0;
        node *a = head;
        while(cur_index != index-1){
           a = a-> next;
           cur_index++;
        }
        node *b = a->next;
        a->next = b->next;
    }

   void removeLast(){
        node *a = head;
        if( a== NULL){
            cout << "empty List"<< endl;
            return;
        }
        while(a ->next ->next != NULL){
            a = a->next;
        }
        a->next = NULL;
    }


    void traverse(){

        if(head == NULL){
            cout << "Linked List is empty" << endl;
        }

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

    int searchValue(int value){
       if(head == NULL){
            cout << "Linked List is empty" << endl;
        }

        else{
            node *temp = head;
            int c=0;
            while(temp != NULL){
                if(temp -> data == value){
                    return c+1;
                }
                else {
                    c++;
                    temp = temp -> next;
                }
            }
        }
        return -1;
    }

    int getValue(int index){

            node *temp = head;
            int c=0;
            while(temp != NULL){
                if(index == c){
                    return temp->data;
                }
                else {
                    c++;
                    temp = temp -> next;
                }
            }
        return -1;
    }

    int getSize(){
        int c = 0;
        if(head == NULL){
            return c;
        }

        else{

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

            return c;
        }

    }

    void printReverse(node *a){
        if(a == NULL){
            return;
        }
        printReverse(a -> next);
        cout << a->data << " ";
    }

    void printReverse1(){
        printReverse(head);
    }

};

int main(){

    linkedList l;

    l.insertAtHead(5);
    l.insertAtHead(2);
    l.insertAtHead(10);
    l.insertAtHead(7);

    cout << "size =  " << l.getSize() << endl;
    cout << "Linked List :";
    l.traverse();

    l.insertAtAnyPos(2 , 20);
    cout << "New size = " << l.getSize() << endl;
    cout << "Linked List :";
    l.traverse();

    cout << "value at index 2 : "<< l.getValue(2) << endl;

    l.deleteFromHead();
    cout << "After delete from head : ";
    l.traverse();

    l.deleteFromIndex(2);
    cout << "After delete from index 2 : ";
    l.traverse();

    l.inserAfterValue(5 , 15);
    cout << "insert after value ";
    l.traverse();

    cout << "Reverse linked List : ";
    l.printReverse1();

    return 0;
}