//Q2.4) WAP to implement a linked list, update data at any position, update a value and then print the linked list.
 
#include <iostream>
#include<stdlib.h>
using namespace std;
 
struct node{
    int data;
    node* next;
    void setData(int d){
        data=d;
        next=NULL;
    }
};
 
void InsertAtHead(node* &head,int data){
    node* newNode=(node*)malloc(sizeof(node));
    newNode->setData(data);
    newNode->next=head;
    head=newNode;
}
 
void InsertAtTail(node* &tail,int data){
    node* newNode=(node*)malloc(sizeof(node));
    newNode->setData(data);
    tail->next=newNode;
    tail=newNode;
}
 
void UpdateAtPosition(node* &head,int position,int newValue){
    node* temp=head;
    int nodeNumber=1;
    while(nodeNumber<position){
        temp=temp->next;
        nodeNumber++;
    }
    temp->data=newValue;
}
void UpdateTheValue(node* head,int oldValue,int newValue){
    node* temp=head;
    while(temp!=NULL){
        if(temp->data==oldValue){
            temp->data=newValue;
        }
        temp=temp->next;
    }
}
void PrintLinkedList(node* &head){
    node* temp=head;
    while(temp!=NULL){
        cout<<temp->data<<" ";
        temp=temp->next;
    }
    cout<<endl;
}
 
int main(){
 
    node* head=(node*)malloc(sizeof(node));
    head->setData(1);
    node* tail=head;
    
    InsertAtHead(head,2);
    InsertAtTail(tail,4);
    InsertAtTail(tail,6);
 
    cout<<"Before Position Updation: ";
    PrintLinkedList(head);
 
    UpdateAtPosition(head,1,6);

    cout<<"After Position Updation: ";
    PrintLinkedList(head);

    cout<<endl;

    cout<<"Before Value Updation: ";
    PrintLinkedList(head);

    UpdateTheValue(head,6,7);
    
    cout<<"After Value Updation: ";
    PrintLinkedList(head);
 
    return 0;
}
/*
    OUTPUT:
 
    Before Position Updation: 2 1 4 6 
    After Position Updation: 6 1 4 6 

    Before Value Updation: 6 1 4 6 
    After Value Updation: 7 1 4 7 
 
*/