C++ program to check whether a number is Palindrome or not

November 23, 2021

palindrome or not in c++

 Palindrome or not

A number is a Palindrome number if the reverse of the number and the numbers itself are equal i.e. if number and its reverse are same then the number is a palindrome number.

Example: Let’s take a number say 2876. Here the reverse of the number is 6782 which is not equal to the number so 2876 is not a palindrome number. 

Let’s take another number say 12121. Here the reverse of the number is 12121 which is equal to the number, so 12121 is a Palindrome number.statement.

Algorithm:-

  1. Take integer number as input and store it in num
  2. store copy of num in temp
  3. we have to extract the digits of number using Modulus % operator
  4. reverse intialized to 0
  5. A  do while loop is started
    • unit digit is extracted and stored in rem

                       rem=num%10;

    •  We have to shift the reverse to left by multiplying by 10 and add remainder to it

                       reverse=reverse*10+rem; 

    • num is divided by 10 and the value is stored in num itself.

                      num/=10;

    • The loop works until num is not equal to 0.

                     while(num!=0);

      5. reverse is printed as output as it is the reverse of the number entered by the user.

      6.  if  temp==reverse print number is palindrome otherwise number is not palindrome

C++ program to check whether a number is Palindrome or not

C++ Code

 //C++ Program
//Palindrome or not
#include 
using namespace std;
//main Program
int main()
{
    int num, digit, reverse = 0;
    cout << "Enter a positive integer: "; //user input cin >> num;
    int temp = num;
    
    
    //loop to find reverse
    while(num!=0)
    {
         digit = num % 10;
         reverse = (reverse * 10) + digit;
         num = num / 10;
    } 
    cout << "The reverse of "<< temp <<" is "<< reverse << endl;
   
    //checking for palindrome
    if (temp == reverse)
          cout << "The number is a palindrome.";
    else
          cout << "The number is not a palindrome.";
    return 0;
}

Output

Enter a positive integer: 2345
The reverse of 2345 is 5432
The number is not a palindrome.
PrepInsta C Cpp Course
List of Top 100 Codes