008_Node_at_given_Index.cpp

//{ Driver Code Starts
// C program to find n'th node in linked list
#include <stdio.h>
#include <stdlib.h>
#include<iostream>
using namespace std;

/* Link list node */
struct node
{
    int data;
    struct node* next;
    
    node(int x){
        data = x;
        next = NULL;
    }
};
 
struct node* push(struct node* head, int d)
{
   
    struct node* new_node =
            (struct node*) malloc(sizeof(struct node));

    new_node->data  = d;
    new_node->next = NULL;
    
    if (head == NULL) return new_node;
    
    struct node* h = head;
    while (head->next != NULL) head = head->next;
    head->next = new_node;
    
    return h;
}

int GetNth(struct node* head, int index);


/* Driver program to test above function*/
int main()
{
  int T,i,n,l,k;
    
    cin>>T;
    
    while(T--){
    struct node *head = NULL;
        
        cin>>n>>k;
        for(i=1;i<=n;i++)
        {
            cin>>l;
            head = push(head, l);
        }
   
    printf("%d\n", GetNth(head, k));  
    getchar();
    }
    return 0;
}
 
// } Driver Code Ends


/* Print he nth node in the linked list Node is defined as 
/* Link list node
struct node
{
    int data;
    struct node* next;
    
    node(int x){
        data = x;
        next = NULL;
    }
}; 
*/

// Should return data of node at given index. The function may
//  assume that there are at least index+1 nodes in linked list
int GetNth(struct node* head, int index){
  // Code here
  node* q;
  int current_index=1;
  for (q=head;q!=NULL;q=q->next)
  {
      if (current_index==index)
      {
          return q->data;
      }
      current_index++;
  }
}