Skip to content
Related Articles

Related Articles

Improve Article
Save Article
Like Article

Generate number with given operation and check if it is palindrome

  • Last Updated : 28 May, 2021

Given an integer N the task is to create a string out of it by repeating the number such that the length of the resultant string is equal to the sum of the digits in the original number. 
For eg: If the number is 61 and the sum of the digits is 6 + 1 = 7 so the string generated after repeating 61 will be of 7 length i.e. 6161616.
Examples: 
 

Input: N = 10101 
Output: Yes 
Length of the string is given by sum of the digits i.e. 1 + 0 + 1 + 0 + 1 = 3. 
So the resultant string is “101” which is a palindrome.
Input: N = 123 
Output: No 
Length of the string will be 1 + 2 3 = 6. 
So the resultant string is “123123” which is not a palindrome. 
 

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.

 



Approach: 
 

  • Find the sum of the digits of N and repeat the number till the length of the string becomes equal to this sum.
  • Now check if the resultant string is a palindrome or not.
  • If it is a palindrome then print Yes.
  • Else print No.

Below is the implementation of the above approach:
 

C++




// CPP implementation of the approach
#include<bits/stdc++.h>
using namespace std;
 
    // Function that returns true if str is a palindrome
    bool isPalindrome(string str)
    {
        int len = str.length();
        for (int i = 0; i < len / 2; i++)
        {
            if (str[i] != str[len - 1 - i])
                return false;
        }
 
        return true;
    }
 
    // Function that returns true if the
    // generated string is a palindrome
    bool createStringAndCheckPalindrome(int N)
    {
 
        // sub contains N as a string
        ostringstream out;
        out << N;
        string result = out.str();
     
        string sub = "" + result, res_str = "";
 
        int sum = 0;
 
        // Calculate the sum of the digits
        while (N > 0)
        {
            int digit = N % 10;
            sum += digit;
            N = N / 10;
        }
 
        // Repeat the substring until the length
        // of the resultant string < sum
        while (res_str.length() < sum)
            res_str += sub;
 
        // If length of the resultant string exceeded sum
        // then take substring from 0 to sum - 1
        if (res_str.length() > sum)
            res_str = res_str.substr(0, sum);
 
        // If the generated string is a palindrome
        if (isPalindrome(res_str))
            return true;
 
        return false;
    }
 
    // Driver code
    int main()
    {
        int N = 10101;
        if (createStringAndCheckPalindrome(N))
            cout << ("Yes");
        else
            cout << ("No");
    }
     
// This code is contributed by
// Shashank_Sharma

Java




// Java implementation of the approach
class GFG {
 
    // Function that returns true if str is a palindrome
    static boolean isPalindrome(String str)
    {
        int len = str.length();
        for (int i = 0; i < len / 2; i++) {
            if (str.charAt(i) != str.charAt(len - 1 - i))
                return false;
        }
 
        return true;
    }
 
    // Function that returns true if the
    // generated string is a palindrome
    static boolean createStringAndCheckPalindrome(int N)
    {
 
        // sub contains N as a string
        String sub = "" + N, res_str = "";
 
        int sum = 0;
 
        // Calculate the sum of the digits
        while (N > 0) {
            int digit = N % 10;
            sum += digit;
            N = N / 10;
        }
 
        // Repeat the substring until the length
        // of the resultant string < sum
        while (res_str.length() < sum)
            res_str += sub;
 
        // If length of the resultant string exceeded sum
        // then take substring from 0 to sum - 1
        if (res_str.length() > sum)
            res_str = res_str.substring(0, sum);
 
        // If the generated string is a palindrome
        if (isPalindrome(res_str))
            return true;
 
        return false;
    }
 
    // Driver code
    public static void main(String args[])
    {
        int N = 10101;
        if (createStringAndCheckPalindrome(N))
            System.out.println("Yes");
        else
            System.out.println("No");
    }
}

Python 3




# Python 3 implementation of the approach
 
# Function that returns true if
# str is a palindrome
def isPalindrome(s):
 
    l = len(s)
    for i in range(l // 2):
        if (s[i] != s[l - 1 - i]):
            return False
    return True
 
# Function that returns true if the
# generated string is a palindrome
def createStringAndCheckPalindrome(N):
     
    # sub contains N as a string
    sub = "" + chr(N)
    res_str = ""
 
    sum = 0
 
    # Calculate the sum of the digits
    while (N > 0) :
        digit = N % 10
        sum += digit
        N = N // 10
 
    # Repeat the substring until the length
    # of the resultant string < sum
    while (len(res_str) < sum):
        res_str += sub
 
    # If length of the resultant string exceeded
    # sum then take substring from 0 to sum - 1
    if (len(res_str) > sum):
        res_str = res_str[0: sum]
 
    # If the generated string is a palindrome
    if (isPalindrome(res_str)):
        return True
 
    return False
 
# Driver code
if __name__ == "__main__":
     
    N = 10101
    if (createStringAndCheckPalindrome(N)):
        print("Yes")
    else:
        print("No")
 
# This code is contributed by ita_c

C#




// C# implementation of the approach
 
using System ;
 
class GFG {
 
    // Function that returns true if str is a palindrome
    static bool isPalindrome(string str)
    {
        int len = str.Length;
        for (int i = 0; i < len / 2; i++) {
            if (str[i] != str[len - 1 - i])
                return false;
        }
 
        return true;
    }
 
    // Function that returns true if the
    // generated string is a palindrome
    static bool createStringAndCheckPalindrome(int N)
    {
 
        // sub contains N as a string
        string sub = "" + N, res_str = "";
 
        int sum = 0;
 
        // Calculate the sum of the digits
        while (N > 0) {
            int digit = N % 10;
            sum += digit;
            N = N / 10;
        }
 
        // Repeat the substring until the length
        // of the resultant string < sum
        while (res_str.Length< sum)
            res_str += sub;
 
        // If length of the resultant string exceeded sum
        // then take substring from 0 to sum - 1
        if (res_str.Length > sum)
            res_str = res_str.Substring(0, sum);
 
        // If the generated string is a palindrome
        if (isPalindrome(res_str))
            return true;
 
        return false;
    }
 
    // Driver code
    public static void Main()
    {
        int N = 10101;
        if (createStringAndCheckPalindrome(N))
            Console.WriteLine("Yes");
        else
            Console.WriteLine("No");
    }
    // This code is contributed by Ryuga
}

Javascript




<script>
 
// JavaScript implementation of the approach
     
     // Function that returns true
     // if str is a palindrome
    function isPalindrome(str)
    {
        let len = str.length;
        for (let i = 0; i < len / 2; i++) {
            if (str[i] != str[len - 1 - i])
                return false;
        }
   
        return true;
    }
     
     // Function that returns true if the
    // generated string is a palindrome
    function createStringAndCheckPalindrome(N)
    {
        // sub contains N as a string
        let sub = "" + N, res_str = "";
   
        let sum = 0;
   
        // Calculate the sum of the digits
        while (N > 0) {
            let digit = N % 10;
            sum += digit;
            N = N / 10;
        }
   
        // Repeat the substring until the length
        // of the resultant string < sum
        while (res_str.length < sum)
            res_str += sub;
   
        // If length of the resultant string exceeded sum
        // then take substring from 0 to sum - 1
        if (res_str.length > sum)
            res_str = res_str.substring(0, sum);
   
        // If the generated string is a palindrome
        if (isPalindrome(res_str))
            return true;
   
        return false;
    }
     
    // Driver code
    let N = 10101;
        if (createStringAndCheckPalindrome(N))
            document.write("Yes");
        else
            document.write("No");
 
 
// This code is contributed by avanitrachhadiya2155
 
</script>
Output: 
Yes

 




My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!