Given a linked list with integer node values, the task is to find the sum of all Palindrome Numbers present as Node values.
Examples:
Input: 13 -> 212 -> 22 -> 44 -> 4 -> 3
Output: 285
Explanation: The sum of palindrome numbers {22, 212, 44, 4, 3} is 285
Input: 19 -> 22 -> 141
Output: 163
Approach: In order to solve this problem we are using an approach similar to calculate the Sum of all Palindromes in an Array. Iterate through all the nodes of the linked list and check if the current node value is a palindrome or not. If so, add the value and store the sum. The final sum of all such values gives the desired answer.
Below is the implementation of the above approach:
C++
// C++ program to calculate// the sum of all palindromic// numbers in a linked list#include <bits/stdc++.h>using namespace std;// Node of the singly// linked liststruct Node { int data; Node* next;};// Function to insert a node at// the beginning of the singly// Linked Listvoid push(Node** head_ref, int new_data){ // allocate node Node* new_node = (Node*)malloc( sizeof(struct Node)); // Insert the data new_node->data = new_data; // Point the new Node // to the current head new_node->next = (*head_ref); // Make the new Node as // the new head (*head_ref) = new_node;}// Function to check// if a number n is// palindrome or notbool isPalin(int n){ int d = 0, s = 0; int temp = n; while (n > 0) { d = n % 10; s = s * 10 + d; n = n / 10; } // If n is equal to // the its reverse // it is a palindrome return temp == s;}// Function to calculate// the sum of all nodes// which are palindromeint sumOfpal(Node* head_1){ int s = 0; Node* ptr = head_1; while (ptr != NULL) { // If the value of the // current node is // a palindrome if (isPalin(ptr->data)) { // Add the value // to the sum s += ptr->data; } ptr = ptr->next; } return s;}// Driver Codeint main(){ // Create the head // of the linked list Node* head1 = NULL; // Insert nodes into // the linked list push(&head1, 13); push(&head1, 212); push(&head1, 22); push(&head1, 44); push(&head1, 4); push(&head1, 3); // Print the sum of all // palindromes cout << sumOfpal(head1) << endl; return 0;} |
Java
// Java program to calculate// the sum of all palindromes// in a linked listimport java.util.*;class GFG { // Node of the singly // linked list static class Node { int data; Node next; }; // Function to insert a node // at the beginning of the // singly Linked List static Node push(Node head_ref, int new_data) { // Allocate node Node new_node = new Node(); // Insert the data new_node.data = new_data; // Point the current Node // to the current head new_node.next = (head_ref); // Make the current node // as the new head (head_ref) = new_node; return head_ref; } // Function to check if // a number is palindrome static boolean isPalin(int n) { int d = 0, s = 0; int temp = n; while (n > 0) { d = n % 10; s = s * 10 + d; n = n / 10; } // If n is equal to its // reverse, it is a // palindrome return temp == s; } // Function to calculate sum // of all nodes with value // which is a palindrome static int sumOfpal(Node head_1) { int s = 0; Node ptr = head_1; while (ptr != null) { // If the value of the // current node // is a palindrome if (isPalin(ptr.data)) { // Add that value to // the sum s += ptr.data; } ptr = ptr.next; } // Return the sum return s; } // Driver Code public static void main(String args[]) { // Create the head Node head1 = null; // Insert nodes to the // Linked List head1 = push(head1, 13); head1 = push(head1, 212); head1 = push(head1, 22); head1 = push(head1, 44); head1 = push(head1, 4); head1 = push(head1, 3); System.out.println( sumOfpal(head1)); }} |
Python3
# Python3 program to # calculate the sum of all # palindromes present in # a Linked Listclass Node: def __init__(self, data): self.data = data self.next = next # Function to insert a # node at the beginning # of the singly Linked List def push( head_ref, new_data) : # Allocate node new_node = Node(0) # Insert data new_node.data = new_data # Point to the head new_node.next = (head_ref) # Make the new Node # the new head (head_ref) = new_node return head_ref # Function to check if # a number is palindrome def isPalin(n) : d = 0; s = 0; temp = n; while (n > 0) : d = n % 10; s = s * 10 + d; n = n // 10; # If n is equal to its reverse, # it is a palindrome return s == temp; # Function to calculate sum of # all elements in a Linked List # which are palindrome def sumOfpal(head_ref1) : s = 0; ptr1 = head_ref1 while (ptr1 != None) : # If the value of the # current node # is a palindrome if (isPalin(ptr1.data)) : # Add that value s = s + ptr1.data # Move to the next node ptr1 = ptr1.next # Return the final sum return s; # Driver code # Create the Headhead1 = None# Insert nodes head1 = push(head1, 13) head1 = push(head1, 212) head1 = push(head1, 22) head1 = push(head1, 44) head1 = push(head1, 4)head1 = push(head1, 3)print(sumOfpal(head1)) |
C#
// C# program to calculate// the sum of all palindromes// in a linked listusing System;class GFG {// Node of the singly// linked listclass Node{ public int data; public Node next;};// Function to insert a node// at the beginning of the// singly Linked Liststatic Node push(Node head_ref, int new_data){ // Allocate node Node new_node = new Node(); // Insert the data new_node.data = new_data; // Point the current Node // to the current head new_node.next = (head_ref); // Make the current node // as the new head (head_ref) = new_node; return head_ref;}// Function to check if// a number is palindromestatic bool isPalin(int n){ int d = 0, s = 0; int temp = n; while (n > 0) { d = n % 10; s = s * 10 + d; n = n / 10; } // If n is equal to its // reverse, it is a // palindrome return temp == s;}// Function to calculate sum// of all nodes with value// which is a palindromestatic int sumOfpal(Node head_1){ int s = 0; Node ptr = head_1; while (ptr != null) { // If the value of the // current node // is a palindrome if (isPalin(ptr.data)) { // Add that value to // the sum s += ptr.data; } ptr = ptr.next; } // Return the sum return s;}// Driver Codepublic static void Main(String []args){ // Create the head Node head1 = null; // Insert nodes to the // Linked List head1 = push(head1, 13); head1 = push(head1, 212); head1 = push(head1, 22); head1 = push(head1, 44); head1 = push(head1, 4); head1 = push(head1, 3); Console.WriteLine(sumOfpal(head1));}}// This code is contributed by sapnasingh4991 |
Javascript
<script> // JavaScript program to calculate // the sum of all palindromes // in a linked list // Node of the singly // linked list class Node { constructor() { this.data = 0; this.next = null; } } // Function to insert a node // at the beginning of the // singly Linked List function push(head_ref, new_data) { // Allocate node var new_node = new Node(); // Insert the data new_node.data = new_data; // Point the current Node // to the current head new_node.next = head_ref; // Make the current node // as the new head head_ref = new_node; return head_ref; } // Function to check if // a number is palindrome function isPalin(n) { var d = 0, s = 0; var temp = n; while (n > 0) { d = n % 10; s = s * 10 + d; n = parseInt(n / 10); } // If n is equal to its // reverse, it is a // palindrome return temp == s; } // Function to calculate sum // of all nodes with value // which is a palindrome function sumOfpal(head_1) { var s = 0; var ptr = head_1; while (ptr != null) { // If the value of the // current node // is a palindrome if (isPalin(ptr.data)) { // Add that value to // the sum s += ptr.data; } ptr = ptr.next; } // Return the sum return s; } // Driver Code // Create the head var head1 = null; // Insert nodes to the // Linked List head1 = push(head1, 13); head1 = push(head1, 212); head1 = push(head1, 22); head1 = push(head1, 44); head1 = push(head1, 4); head1 = push(head1, 3); document.write(sumOfpal(head1)); // This code is contributed by rdtank. </script> |
Output:
285
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