problem_010.cpp

//Write a program to implement a linkedlist, 
//with the option to insert a node into it at the user given position

#include<iostream>
using namespace std;

struct Node{
    int data;
    struct Node* next;
};
void CreateList(struct Node* *root,int value){
    struct Node* ptr=*root;
    struct Node* temp= new Node();
    temp->data=value;
    temp->next=NULL;
    if(*root == NULL){
        *root=temp;
    }else{
        while(ptr->next !=NULL){
            ptr=ptr->next;
        }
        ptr->next=temp;
    }
}
void insertNode(struct Node* *root,int value,int pos){
    struct Node* ptr=*root;
    struct Node* temp= new Node();
    temp->data=value;
    if(*root == NULL){
        *root=temp;
        temp->next=NULL;
    }else{
        
        int i=1;
        while(i<pos-1){
            ptr=ptr->next;
            i++;
        }
        struct Node* afterNode=ptr->next;

        ptr->next=temp;
        temp->next=afterNode;
    }
}
void display(struct Node* root){
    struct Node* ptr=root;
    
    while(ptr!=NULL){
        cout<<ptr->data<<"->";
        ptr=ptr->next;
    }
    cout<<"Null"<<endl;
}
int main(){ 
    struct Node* root=NULL;

    CreateList(&root,12);
    CreateList(&root,15);
    CreateList(&root,17);
    CreateList(&root,22);
    display(root);

    insertNode(&root,45,3);
    display(root);

    return 0;
}