链接列表中所有回文数的总和

给定一个带有整数节点值的链表，任务是找到所有以节点值形式出现的回文数之和。

例子：

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

方法：为了解决此问题，我们使用一种类似的方法来计算数组中所有回文的总和。遍历链接列表的所有节点，并检查当前节点值是否是回文。如果是这样，则将值相加并存储和。所有这些值的最终总和给出了所需的答案。

下面是上述方法的实现：

C++

// C++ program to calculate
// the sum of all palindromic
// numbers in a linked list
  
#include 
using namespace std;
  
// Node of the singly
// linked list
struct Node {
    int data;
    Node* next;
};
  
// Function to insert a node at
// the beginning of the singly
// Linked List
void 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 not
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
    // the its reverse
    // it is a palindrome
    return temp == s;
}
  
// Function to calculate
// the sum of all nodes
// which are palindrome
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 the value
            // to the sum
            s += ptr->data;
        }
        ptr = ptr->next;
    }
    return s;
}
  
// Driver Code
int 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 list
  
import 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 List
  
class 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) : 
      
    # Alocate node  
    new_node = Node(0)  
      
    # Insert data  
    new_node.data = new_data  
      
    # Pont 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 Head
head1 = 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 list
using System;
  
class GFG {
  
// Node of the singly
// linked list
class Node
{
    public int data;
    public 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 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 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);
  
    Console.WriteLine(sumOfpal(head1));
}
}
  
// This code is contributed by sapnasingh4991

输出：

285