Linked List Sum of Nodes Between 0s

Last Updated : 27 Jul, 2022

Given a linked list which contains a series of numbers separated by “0”. Add them and store them in the linked list in-place.

Note: There will not be continuous zeros in input.

Examples: 

Input  : 1->2->3->0->5->4->0->3->2->0
Output : 6->9->5

Input  : 1->2->3->4
Output : 1->2->3->4
  1. Start iterating over nodes of the linked list.
  2. Iterate while temp.data !=0, and add these data into a variable 'sum'.
  3. When you encounter 0 as the node's data, change pointers of previous nodes.

Implementation:

C++ 
// C++ program to in-place add linked list 
// nodes between 0s.
#include <bits/stdc++.h>
using namespace std;
#define NODE struct node

// Structure of a node
NODE
{
    int data;
    struct node *next;
};

// Function to create a node
NODE *getNode(int val)
{
    NODE *temp;
    temp = (NODE*)malloc(sizeof(NODE));
    temp->data = val;
    temp->next = NULL;
    return temp;
}

// Function to traverse and print Linked List 
void printList(NODE *head)
{
    while(head->next)
    {
        cout << head->data << "-> ";
        head = head->next;
    }
    cout << "->" << head->data ;
}

void inPlaceStore(NODE *head)
{
    
    // Function to store numbers till 0 
    if(head->data == 0)
    {
        head = head->next;
    }
    
    // To store modified list 
    NODE *res = head;
    
    // Traverse linked list and keep 
    // adding nodes between 0s. 
    NODE *temp = head;
    int sum = 0;
    
    while(temp)
    {
        
        // loop to sum the data of nodes till 
        // it encounters 0 
        if(temp->data != 0)
        {
            sum += temp->data;
            temp = temp->next;
        }
        
        // If we encounters 0, we need 
        // to update next pointers 
        else
        {
            res->data = sum;
            res->next = temp->next;
            temp = temp->next;
            res = temp;
            sum = 0;
        }
    }
    printList(head);
}

// Driver Code
int main() 
{
    
    NODE *head;
    head = getNode(3);
    head->next = getNode(2);
    head->next->next = getNode(0);
    head->next->next->next = getNode(4);
    head->next->next->next->next = getNode(5);
    head->next->next->next->next->next = getNode(0);
    head->next->next->next->next->next->next = getNode(6);
    head->next->next->next->next->next->next->next = getNode(7);
    inPlaceStore(head);
    return 0;
}

// This code is contributed by shivanisinghss2110
C 
// C program to in-place add linked list 
// nodes between 0s.
#include <stdio.h>
#include<stdlib.h>
#define NODE struct node

// Structure of a node
NODE
{
    int data;
    struct node *next;
};

// Function to create a node
NODE *getNode(int val)
{
    NODE *temp;
    temp = (NODE*)malloc(sizeof(NODE));
    temp->data = val;
    temp->next = NULL;
    return temp;
}

// Function to traverse and print Linked List 
void printList(NODE *head)
{
    while(head->next)
    {
        printf("%d->",head->data);
        head = head->next;
    }
    printf("%d\n",head->data);
}

void inPlaceStore(NODE *head)
{
    
    // Function to store numbers till 0 
    if(head->data == 0)
    {
        head = head->next;
    }
    
    // To store modified list 
    NODE *res = head;
    
    // Traverse linked list and keep 
    // adding nodes between 0s. 
    NODE *temp = head;
    int sum = 0;
    
    while(temp)
    {
        
        // loop to sum the data of nodes till 
        // it encounters 0 
        if(temp->data != 0)
        {
            sum+=temp->data;
            temp = temp->next;
        }
        
        
        // If we encounters 0, we need 
        // to update next pointers 
        else
        {
            
            res->data = sum;
            res->next = temp->next;
            temp = temp->next;
            res = temp;
            sum = 0;
        }
    }
    printList(head);
}

// Driver Code
int main() 
{
    
    NODE *head;
    head = getNode(3);
    head->next = getNode(2);
    head->next->next = getNode(0);
    head->next->next->next = getNode(4);
    head->next->next->next->next = getNode(5);
    head->next->next->next->next->next = getNode(0);
    head->next->next->next->next->next->next = getNode(6);
    head->next->next->next->next->next->next->next = getNode(7);
    inPlaceStore(head);
    return 0;
}

// This code is contributed by 
// Kaustav kumar Chanda
Java 
// Java program to in-place add linked list 
// nodes between 0s.
class Node {
    int data;
    Node next;

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

public class inPlaceStoreLL {

    // Function to store numbers till 0
    static void inPlaceStore(Node head)
    {     
        if(head.data == 0){ 
           head = head.next;
        }
       
        // To store modified list 
        Node res = head;

        // Traverse linked list and keep
        // adding nodes between 0s.
        Node temp = head; 
        int sum = 0;
        while (temp != null) {
            
            
            
            // loop to sum the data of nodes till 
            // it encounters 0
            if (temp.data != 0) {
                sum += temp.data;
                temp = temp.next;
            }

            // If we encounters 0, we need 
            // to update next pointers
            else {
                res.data = sum;
                res.next = temp.next;
                temp = res.next;
                res = res.next;
                sum = 0;
            }
        }
        printList(head);
    }

    // Function to traverse and print Linked List
    static void printList(Node head)
    {
        while (head.next != null) {
            System.out.print(head.data + "-> ");
            head = head.next;
        }
        System.out.println(head.data);
    }

    // Driver Code
    public static void main(String[] args)
    {
        Node head = new Node(3);
                head.next = new Node(2);
                head.next.next = new Node(0);
                head.next.next.next = new Node(4);
                head.next.next.next.next = new Node(5);
                head.next.next.next.next.next = new Node(0);
                head.next.next.next.next.next.next = new Node(6);
                head.next.next.next.next.next.next.next = new Node(7);
        inPlaceStore(head);
        
    }
}
Python3 
# Python3 program to in-place add linked list 
# nodes between 0s.
 
# Structure of a node
class Node:
    
    def __init__(self, data):
        
        self.data = data
        self.next = None

# Function to create a node
def getNode(val):
    
    temp = Node(val)
    return temp
    
# Function to traverse and print Linked List 
def printList(head):

    while (head.next):
        print(head.data, end = "-> ")
        head = head.next
    
    print("->" + str(head.data), end = '')

def inPlaceStore(head):
     
    # Function to store numbers till 0 
    if (head.data == 0):
        head = head.next
    
    # To store modified list 
    res = head
     
    # Traverse linked list and keep 
    # adding nodes between 0s. 
    temp = head
    sum = 0
     
    while (temp):
         
        # Loop to sum the data of nodes till 
        # it encounters 0 
        if (temp.data != 0):
            sum += temp.data
            temp = temp.next
        
        # If we encounters 0, we need 
        # to update next pointers 
        else:
            res.data = sum
            res.next = temp.next
            temp = temp.next
            res = temp
            sum = 0
        
    printList(head)

# Driver Code
if __name__=='__main__':
     
    head = getNode(3)
    head.next = getNode(2)
    head.next.next = getNode(0)
    head.next.next.next = getNode(4)
    head.next.next.next.next = getNode(5)
    head.next.next.next.next.next = getNode(0)
    head.next.next.next.next.next.next = getNode(6)
    head.next.next.next.next.next.next.next = getNode(7)
    
    inPlaceStore(head)
    
# This code is contributed by rutvik_56
C# 
// C# program to in-place add linked list 
// nodes between 0s. 
using System;

public class Node 
{ 
    public int data; 
    public Node next; 

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

public class inPlaceStoreLL 
{ 

    // Function to store numbers till 0 
    static void inPlaceStore(Node head) 
    { 
        if(head.data == 0)
        { 
            head = head.next; 
        } 
        
        // To store modified list 
        Node res = head; 

        // Traverse linked list and keep 
        // adding nodes between 0s. 
        Node temp = head; 
        int sum = 0; 
        while (temp != null) 
        { 
            
            // loop to sum the data of nodes till 
            // it encounters 0 
            if (temp.data != 0)
            { 
                sum += temp.data; 
                temp = temp.next; 
            } 

            // If we encounters 0, we need 
            // to update next pointers 
            else
            { 
                res.data = sum; 
                res.next = temp.next; 
                temp = res.next; 
                res = res.next; 
                sum = 0; 
            } 
        } 
        printList(head); 
    } 

    // Function to traverse and print Linked List 
    static void printList(Node head) 
    { 
        while (head.next != null)
        { 
            Console.Write(head.data + "-> "); 
            head = head.next; 
        } 
        Console.WriteLine(head.data); 
    } 

    // Driver Code 
    public static void Main() 
    { 
        Node head = new Node(3); 
        head.next = new Node(2); 
        head.next.next = new Node(0); 
        head.next.next.next = new Node(4); 
        head.next.next.next.next = new Node(5); 
        head.next.next.next.next.next = new Node(0); 
        head.next.next.next.next.next.next = new Node(6); 
        head.next.next.next.next.next.next.next = new Node(7); 
        inPlaceStore(head); 
    } 
} 

/* This code is contributed PrinciRaj1992 */
JavaScript 
<script>

// JavaScript program to in-place add linked list
// nodes between 0s.

class Node
{
    constructor(data)
    {
        this.data=data;
        this.next = null;
    }
}

// Function to store numbers till 0
function inPlaceStore(head)
{
    if(head.data == 0){
           head = head.next;
        }
        
        // To store modified list
        let res = head;
 
        // Traverse linked list and keep
        // adding nodes between 0s.
        let temp = head;
        let sum = 0;
        while (temp != null) {
             
             
             
            // loop to sum the data of nodes till
            // it encounters 0
            if (temp.data != 0) {
                sum += temp.data;
                temp = temp.next;
            }
 
            // If we encounters 0, we need
            // to update next pointers
            else {
                res.data = sum;
                res.next = temp.next;
                temp = res.next;
                res = res.next;
                sum = 0;
            }
        }
        printList(head);
}

// Function to traverse and print Linked List
function  printList(head)
{
    while (head.next != null) {
            document.write(head.data + "-> ");
            head = head.next;
        }
        document.write(head.data);
}

// Driver Code
let head = new Node(3);
head.next = new Node(2);
head.next.next = new Node(0);
head.next.next.next = new Node(4);
head.next.next.next.next = new Node(5);
head.next.next.next.next.next = new Node(0);
head.next.next.next.next.next.next = new Node(6);
head.next.next.next.next.next.next.next = new Node(7);
inPlaceStore(head);



// This code is contributed by rag2127

</script>

Output
5-> 9-> 6-> ->7
Comment
Article Tags:
Misc
Linked List
DSA
Microsoft

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