Sum of the nodes of a Singly Linked List

Given a singly linked list. The task is to find the sum of nodes of the given linked list.

Task is to do A + B + C + D.


Examples:

Input: 7->6->8->4->1
Output: 26
Sum of nodes:
7 + 6 + 8 + 4 + 1 = 26

Input: 1->7->3->9->11->5
Output: 36

Recursive Solution:



  • Call a function by passing the head and variable to store the sum.
    • Then recursively call the function by passing the next of current node and sum variable.
      • Add the value of the current node to the sum.

Below is the implementation of above approach:

C++

filter_none

edit
close

play_arrow

link
brightness_4
code

// C++ implementation to find the sum of
// nodes of the Linked List
#include <bits/stdc++.h>
using namespace std;
  
/* A Linked list node */
struct Node {
    int data;
    struct Node* next;
};
  
// function to insert a node at the
// beginning of the linked list
void push(struct Node** head_ref, int new_data)
{
    /* allocate node */
    struct Node* new_node = new Node;
  
    /* put in the data */
    new_node->data = new_data;
  
    /* link the old list to the new node */
    new_node->next = (*head_ref);
  
    /* move the head to point to the new node */
    (*head_ref) = new_node;
}
  
// function to recursively find the sum of
// nodes of the given linked list
void sumOfNodes(struct Node* head, int* sum)
{
    // if head = NULL
    if (!head)
        return;
  
    // recursively traverse the remaining nodes
    sumOfNodes(head->next, sum);
  
    // accumulate sum
    *sum = *sum + head->data;
}
  
// utility function to find the sum of  nodes
int sumOfNodesUtil(struct Node* head)
{
  
    int sum = 0;
  
    // find the sum of  nodes
    sumOfNodes(head, &sum);
  
    // required sum
    return sum;
}
  
// Driver program to test above
int main()
{
    struct Node* head = NULL;
  
    // create linked list 7->6->8->4->1
    push(&head, 7);
    push(&head, 6);
    push(&head, 8);
    push(&head, 4);
    push(&head, 1);
  
    cout << "Sum of nodes = "
         << sumOfNodesUtil(head);
    return 0;
}

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java implementation to find the sum of 
// nodes of the Linked List 
class GFG 
{
      
static int sum=0;
      
// A Linked list node /
static class Node
    int data; 
    Node next; 
  
// function to insert a node at the 
// beginning of the linked list 
static Node push( Node head_ref, int new_data) 
    // allocate node /
    Node new_node = new Node(); 
  
    // put in the data /
    new_node.data = new_data; 
  
    // link the old list to the new node /
    new_node.next = (head_ref); 
  
    // move the head to point to the new node /
    (head_ref) = new_node; 
    return head_ref;
  
// function to recursively find the sum of 
// nodes of the given linked list 
static void sumOfNodes( Node head) 
    // if head = null 
    if (head == null
        return
  
    // recursively traverse the remaining nodes 
    sumOfNodes(head.next); 
  
    // accumulate sum 
    sum = sum + head.data; 
  
// utility function to find the sum of nodes 
static int sumOfNodesUtil( Node head) 
  
    sum = 0
  
    // find the sum of nodes 
    sumOfNodes(head); 
  
    // required sum 
    return sum; 
  
// Driver program to test above 
public static void main(String args[])
    Node head = null
  
    // create linked list 7.6.8.4.1 
    head = push(head, 7); 
    head = push(head, 6); 
    head = push(head, 8); 
    head = push(head, 4); 
    head = push(head, 1); 
  
    System.out.println( "Sum of nodes = "
        + sumOfNodesUtil(head)); 
}
  
// This code is contributed by Arnab Kundu

chevron_right


Python3

filter_none

edit
close

play_arrow

link
brightness_4
code

# Python3 implementation to find the sum of 
# nodes of the Linked List 
import math
  
# class for a Sum
class Sum:
    tsum = None
  
# A Linked list node 
class Node:
    def __init__(self,data):
        self.data = data
        self.next = None
  
# function to insert a node at the 
# beginning of the linked list 
def push(head, data):
    if not head:
        return Node(data)
  
    # put in the data 
    # and allocate node 
    new_node = Node(data)
  
    # link the old list to the new node 
    new_node.next = head
  
    # move the head to point
    # to the new node 
    head = new_node
    return head
  
# function to recursively find  
# the sum of nodes of the given
# linked list 
def sumOfNode(head, S):
      
    # if head = NULL
    if not head:
        return
      
    # recursively traverse the 
    # remaining nodes
    sumOfNode(head.next, S)
      
    # accumulate sum
    S.tsum += head.data 
  
# utility function to find 
# the sum of nodes
def sumOfNodesUtil(head):
    S = Sum()
    S.tsum = 0
      
    # find the sum of nodes
    sumOfNode(head, S)
      
    # required sum
    return S.tsum
  
# Driver Code
if __name__=='__main__':
    head = None
  
    # create linked list 7->6->8->4->1 
    head = push(head, 7)
    head = push(head, 6)
    head = push(head, 8)
    head = push(head, 4)
    head = push(head, 1)
    print("Sum of Nodes = {}"
           format(sumOfNodesUtil(head)))
  
# This code is contributed 
# by Vikash Kumar 37

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# implementation to find the sum of 
// nodes of the Linked List 
using System;
  
class GFG 
    public static int sum = 0; 
          
    // A Linked list node / 
    public class Node 
    
        public int data; 
        public Node next; 
    
      
    // function to insert a node at the 
    // beginning of the linked list 
    static Node push(Node head_ref, int new_data) 
    
        // allocate node / 
        Node new_node = new Node(); 
      
        // put in the data / 
        new_node.data = new_data; 
      
        // link the old list to the new node / 
        new_node.next = (head_ref); 
      
        // move the head to point to the new node / 
        (head_ref) = new_node; 
        return head_ref; 
    
      
    // function to recursively find the sum of 
    // nodes of the given linked list 
    static void sumOfNodes(Node head) 
    
        // if head = null 
        if (head == null
            return
      
        // recursively traverse the remaining nodes 
        sumOfNodes(head.next); 
      
        // accumulate sum 
        sum = sum + head.data; 
    
      
    // utility function to find the sum of nodes 
    static int sumOfNodesUtil(Node head) 
    
        sum = 0; 
      
        // find the sum of nodes 
        sumOfNodes(head); 
      
        // required sum 
        return sum; 
    
      
    // Driver program to test above 
    public static void Main(String[] args) 
    
        Node head = null
      
        // create linked list 7.6.8.4.1 
        head = push(head, 7); 
        head = push(head, 6); 
        head = push(head, 8); 
        head = push(head, 4); 
        head = push(head, 1); 
      
        Console.WriteLine("Sum of nodes = " +
                           sumOfNodesUtil(head)); 
    
  
// This code is contributed by Rajput-Ji

chevron_right


Output:

Sum of nodes = 26

Time Complexity: O(N) , N is the number of nodes in a linked list.
Auxiliary Space: O(N), only if the stack size is considered during recursive calls.

Iterative Solution:

  1. Initialise a pointer ptr with the head of the linked list and a sum variable with 0.
  2. Start traversing the linked list using a loop until all the nodes get traversed.
    • Add the value of current node to the sum i.e. sum += ptr -> data .
    • Increment the pointer to the next node of linked list i.e. ptr = ptr ->next .
  3. Return the sum.

Below is the implementation of above approach:

C++

filter_none

edit
close

play_arrow

link
brightness_4
code

// C++ implementation to find the sum of
// nodes of the Linked List
#include <bits/stdc++.h>
using namespace std;
  
/* A Linked list node */
struct Node {
    int data;
    struct Node* next;
};
  
// function to insert a node at the
// beginning of the linked list
void push(struct Node** head_ref, int new_data)
{
    /* allocate node */
    struct Node* new_node = new Node;
  
    /* put in the data */
    new_node->data = new_data;
  
    /* link the old list to the new node */
    new_node->next = (*head_ref);
  
    /* move the head to point to the new node */
    (*head_ref) = new_node;
}
  
// function to find the sum of
// nodes of the given linked list
int sumOfNodes(struct Node* head)
{
    struct Node* ptr = head;
    int sum = 0;
    while (ptr != NULL) {
  
        sum += ptr->data;
        ptr = ptr->next;
    }
  
    return sum;
}
  
// Driver program to test above
int main()
{
    struct Node* head = NULL;
  
    // create linked list 7->6->8->4->1
    push(&head, 7);
    push(&head, 6);
    push(&head, 8);
    push(&head, 4);
    push(&head, 1);
  
    cout << "Sum of nodes = "
         << sumOfNodes(head);
    return 0;
}

chevron_right


Java

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java implementation to find the sum of
// nodes of the Linked List
  
class GFG 
{
  
static Node head; 
  
/* A Linked list node */
static class Node
{
    int data;
    Node next;
};
  
// function to insert a node at the
// beginning of the linked list
// Inserting node at the beginning
static Node push(Node head_ref, int new_data)
{
    /* allocate node */
    Node new_node = new Node();
      
    /* put in the data */
    new_node.data = new_data;
      
    /* link the old list to the new node */
    new_node.next = head_ref;
      
    /* move the head to point to the new node */
    head_ref = new_node;
    return head=head_ref;
}
  
// function to find the sum of
// nodes of the given linked list
static int sumOfNodes( Node head)
{
    Node ptr = head;
    int sum = 0;
    while (ptr != null
    {
  
        sum += ptr.data;
        ptr = ptr.next;
    }
  
    return sum;
}
  
// Driver code
public static void main(String[] args)
{
    // create linked list 7.6.8.4.1
    push(head, 7);
    push(head, 6);
    push(head, 8);
    push(head, 4);
    push(head, 1);
  
    System.out.println("Sum of nodes = "
        + sumOfNodes(head));
}
}
  
/* This code is contributed by PrinciRaj1992 */

chevron_right


C#

filter_none

edit
close

play_arrow

link
brightness_4
code

// C# implementation to find the sum of 
// nodes of the Linked List 
using System;
  
class GFG 
  
static Node head; 
  
/* A Linked list node */
public class Node 
    public int data; 
    public Node next; 
}; 
  
// function to insert a node at the 
// beginning of the linked list 
// Inserting node at the beginning 
static Node push(Node head_ref, int new_data) 
    /* allocate node */
    Node new_node = new Node(); 
      
    /* put in the data */
    new_node.data = new_data; 
      
    /* link the old list to the new node */
    new_node.next = head_ref; 
      
    /* move the head to point to the new node */
    head_ref = new_node; 
    return head=head_ref; 
  
// function to find the sum of 
// nodes of the given linked list 
static int sumOfNodes( Node head) 
    Node ptr = head; 
    int sum = 0; 
    while (ptr != null
    
  
        sum += ptr.data; 
        ptr = ptr.next; 
    
  
    return sum; 
  
// Driver code 
public static void Main(String[] args) 
    // create linked list 7.6.8.4.1 
    push(head, 7); 
    push(head, 6); 
    push(head, 8); 
    push(head, 4); 
    push(head, 1); 
  
    Console.WriteLine("Sum of nodes = "
        + sumOfNodes(head)); 
  
// This code is contributed by 29AjayKumar

chevron_right


Output:

Sum of nodes = 26

Time Complexity: O(N) , N is the number of nodes in a linked list.
Auxiliary Space: O(1)



My Personal Notes arrow_drop_up

Strategy Path planning and Destination matters in success No need to worry about in between temporary failures

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.