Sum of all palindrome numbers present in an Array

Last Updated : 04 May, 2021

Given an array arr[] of N positive integers. The task is to find the sum of all palindrome numbers present in the array. Print the total sum.

A palindrome number is a number which when reversed is equal to the initial number. Example: 121 is palindrome(reverse(121) = 121), 123 is not palindrome(reverse(123) = 321).

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Note: Consider palindrome numbers of length greater than 1 while calculating the sum.

Examples:

Input : arr[] ={12, 313, 11, 44, 9, 1} 
Output : 368

Input : arr[] = {12, 11, 121}
Output : 132

Approach: The idea is to implement a reverse function that reverses a number from the right to left. Implement a function that checks for palindrome numbers and finally traverse the array and calculate sum of all elements which are palindrome.

Below is the implementation of the above approach:

C++

// C++ program to calculate the sum of all
// palindromic numbers in array
#include<bits/stdc++.h>
using namespace std;
 
// Function to reverse a number n
int reverse(int n)
{
    int d = 0, s = 0;
 
    while (n > 0)
    {
        d = n % 10;
        s = s * 10 + d;
        n = n / 10;
    }
 
    return s;
}
 
// Function to check if a number n is
// palindrome
bool isPalin(int n)
{
    // If n is equal to the reverse of n
    // it is a palindrome
    return n == reverse(n);
}
 
// Function to calculate sum of all array
// elements which are palindrome
int sumOfArray(int arr[], int n)
{
    int s = 0;
 
    for (int i = 0; i < n; i++)
    {
        if ((arr[i] > 10) && isPalin(arr[i]))
        {
 
            // summation of all palindrome numbers
            // present in array
            s += arr[i];
        }
    }
    return s;
}
 
// Driver Code
int main()
{
    int n = 6;
 
    int arr[] = { 12, 313, 11, 44, 9, 1 };
 
    cout << sumOfArray(arr, n);
    return 0;
}
 
// This code is contributed by mits

Java

// Java program to calculate the sum of all
// palindromic numbers in array
 
class GFG {
 
    // Function to reverse a number n
    static int reverse(int n)
    {
        int d = 0, s = 0;
 
        while (n > 0) {
            d = n % 10;
            s = s * 10 + d;
            n = n / 10;
        }
 
        return s;
    }
 
    // Function to check if a number n is
    // palindrome
    static boolean isPalin(int n)
    {
        // If n is equal to the reverse of n
        // it is a palindrome
        return n == reverse(n);
    }
 
    // Function to calculate sum of all array
    // elements which are palindrome
    static int sumOfArray(int[] arr, int n)
    {
        int s = 0;
 
        for (int i = 0; i < n; i++) {
            if ((arr[i] > 10) && isPalin(arr[i])) {
 
                // summation of all palindrome numbers
                // present in array
                s += arr[i];
            }
        }
 
        return s;
    }
 
    // Driver Code
    public static void main(String[] args)
    {
        int n = 6;
 
        int[] arr = { 12, 313, 11, 44, 9, 1 };
 
        System.out.println(sumOfArray(arr, n));
    }
}

C#

// C# program to calculate the sum of all
// palindromic numbers in array
using System;
 
class GFG
{
 
    // Function to reverse a number n
    static int reverse(int n)
    {
        int d = 0, s = 0;
 
        while (n > 0)
        {
            d = n % 10;
            s = s * 10 + d;
            n = n / 10;
        }
 
        return s;
    }
 
    // Function to check if a number n is
    // palindrome
    static bool isPalin(int n)
    {
        // If n is equal to the reverse of n
        // it is a palindrome
        return n == reverse(n);
    }
 
    // Function to calculate sum of all array
    // elements which are palindrome
    static int sumOfArray(int[] arr, int n)
    {
        int s = 0;
 
        for (int i = 0; i < n; i++)
        {
            if ((arr[i] > 10) && isPalin(arr[i]))
            {
 
                // summation of all palindrome numbers
                // present in array
                s += arr[i];
            }
        }
 
        return s;
    }
 
    // Driver Code
    public static void Main(String[] args)
    {
        int n = 6;
 
        int[] arr = { 12, 313, 11, 44, 9, 1 };
 
        Console.WriteLine(sumOfArray(arr, n));
    }
}
 
/* This code contributed by PrinciRaj1992 */

Python3

# Python3 program to calculate the sum of all
# palindromic numbers in array
 
# Function to reverse a number n
def reverse(n) :
     
    d = 0; s = 0;
 
    while (n > 0) :
 
        d = n % 10;
        s = s * 10 + d;
        n = n // 10;
 
    return s;
     
 
# Function to check if a number n is
# palindrome
def isPalin(n) :
 
    # If n is equal to the reverse of n
    # it is a palindrome
    return n == reverse(n);
 
 
# Function to calculate sum of all array
# elements which are palindrome
def sumOfArray(arr, n) :
    s = 0;
     
    for i in range(n) :
        if ((arr[i] > 10) and isPalin(arr[i])) :
         
            # summation of all palindrome numbers
            # present in array
            s += arr[i];
             
    return s;
  
 
# Driver Code
if __name__ == "__main__" :
 
    n = 6;
 
    arr = [ 12, 313, 11, 44, 9, 1 ];
 
    print(sumOfArray(arr, n));
    
    # This code is contributed by AnkitRai01

Javascript

<script>
 
// Javascript program to calculate the
// sum of all palindromic numbers in array
 
// Function to reverse a number n
function reverse( n)
{
    let d = 0, s = 0;
 
    while (n > 0)
    {
        d = n % 10;
        s = s * 10 + d;
        n = Math.floor(n / 10);
    }
    return s;
}
 
// Function to check if a number n is
// palindrome
function isPalin(n)
{
     
    // If n is equal to the reverse of n
    // it is a palindrome
    return n == reverse(n);
}
 
// Function to calculate sum of all array
// elements which are palindrome
function sumOfArray( arr, n)
{
    let s = 0;
 
    for(let i = 0; i < n; i++)
    {
        if ((arr[i] > 10) && isPalin(arr[i]))
        {
             
            // Summation of all palindrome
            // numbers present in array
            s += arr[i];
        }
    }
    return s;
}
 
// Driver Code
let n = 6;
let arr = [ 12, 313, 11, 44, 9, 1 ];
 
document.write(sumOfArray(arr, n));
 
// This code is contributed by jana_sayantan
 
</script>

Output:

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Sum of all palindrome numbers present in an Array

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