We use cookies to ensure you have the best browsing experience on our website. Please read our cookie policy for more information about how we use cookies.
  1. Practice
  2. Data Structures
  3. Linked Lists
  4. Insert a node at the head of a linked list
  5. Discussions

Insert a node at the head of a linked list

  • SutaxKapoor + 3 comments

    still not fixed

    • kunal_tyagi + 6 comments

      Its working in C, try this out. All test case passed SinglyLinkedListNode* insertNodeAtHead(SinglyLinkedListNode* llist, int data) {

      SinglyLinkedListNode* temp = (SinglyLinkedListNode*)malloc(sizeof(SinglyLinkedListNode));
temp->data = data;
temp->next = NULL;

if(llist == NULL){
    llist = temp;
}else{
    temp->next = llist;
    llist = temp;
}
return llist;

      }

      • zakarh + 0 comments

        Stop with the comments. Let this comment thread die.

      • ch_krishnapriya + 0 comments

        I dont see a need for if condition here.

        SinglyLinkedListNode* temp = (SinglyLinkedListNode*)malloc(sizeof(SinglyLinkedListNode)); temp->data = data; temp->next = llist; return temp;

      • lavanyamanohar12 + 1 comment
        [deleted]
        • lavanyamanohar12 + 0 comments

          for c++, the following code worked, SinglyLinkedListNode *pNew= new SinglyLinkedListNode(data); if(llist == nullptr){ llist = pNew; }else{ pNew->next = llist; llist = pNew; } return llist;

      • dwivedihimanshu + 1 comment

        hi kunal, i have written same login in java but it is not working for me it is printing only last value of the node which is added, rest of the value is not printing so it is failing.

        • rock_vikash21 + 0 comments

          import java.io.; import java.math.; import java.security.; import java.text.; import java.util.; import java.util.concurrent.; import java.util.regex.*;

          public class Solution {

          static class SinglyLinkedListNode {
    public int data;
    public SinglyLinkedListNode next;

    public SinglyLinkedListNode(int nodeData) {
        this.data = nodeData;
        this.next = null;
    }
}

static class SinglyLinkedList {
    public SinglyLinkedListNode head;
    public SinglyLinkedListNode tail;

    public SinglyLinkedList() {
        this.head = null;
        this.tail = null;
    }


}

public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter) throws IOException {
    while (node != null) {
        bufferedWriter.write(String.valueOf(node.data));

        node = node.next;

        if (node != null) {
            bufferedWriter.write(sep);
        }
    }
}

// Complete the insertNodeAtHead function below.

/*
 * For your reference:
 *
 * SinglyLinkedListNode {
 *     int data;
 *     SinglyLinkedListNode next;
 * }
 *
 */
static SinglyLinkedListNode insertNodeAtHead(SinglyLinkedListNode llist, int data) {


    SinglyLinkedListNode newNode = new SinglyLinkedListNode(data) ;
    if(llist == null) {  
        llist = newNode;
        return llist;  
    }else{

        newNode.next = llist; 
        return newNode;
    } 

}

private static final Scanner scanner = new Scanner(System.in);
      • apdebian + 1 comment

        can u please give the solution of "Insert a Node at the Tail of a Linked List

        " using c.

        • apdebian + 0 comments

          https://www.hackerrank.com/challenges/insert-a-node-at-the-tail-of-a-linked-list/problem

      • shashi1iitk + 0 comments

        SinglyLinkedListNode* temp =(SinglyLinkedListNode*)malloc(sizeof(SinglyLinkedListNode)); temp->data = data; temp->next = llist;

        return temp;

    • shubham1297kumar + 0 comments

      still not fixed

    • chhayaprakashj + 0 comments

      this code in c++ worked: -

      SinglyLinkedListNode* insertNodeAtHead(SinglyLinkedListNode* llist, int data) {

      //llist->next=NULL;
SinglyLinkedListNode *temp=new SinglyLinkedListNode(data);
if(llist==NULL){
    return new SinglyLinkedListNode(data);
}
else{
    temp->next=llist;
    temp->data=data;
    llist=temp;
}
return llist;

      }