Reversing Numbers in C#: An Efficient Algorithm for Integer Reversal

Learn how to reverse an integer in C#. This tutorial provides a concise C# program that implements an integer reversal algorithm, explains its logic, and demonstrates a common programming task useful in various number manipulation and algorithm implementations.

Reversing Numbers in C#

Understanding Number Reversal

Reversing a number means writing its digits in reverse order. For example, the reverse of 123 is 321. This is a common programming task used for various number manipulation and algorithm implementations.

Algorithm for Number Reversal

  1. Get the number as input from the user.
  2. Store the original number in a temporary variable.
  3. Repeatedly extract the last digit using the modulo operator (%).
  4. Build the reversed number by multiplying the current reversed number by 10 and adding the extracted digit.
  5. Divide the original number by 10 to remove the last digit.
  6. Repeat steps 3-5 until the original number becomes 0.
  7. Compare the original number and the reversed number; if they are the same, it's a palindrome.

C# Program to Reverse a Number

This C# program implements the algorithm to reverse an integer. It takes user input, reverses the number using arithmetic operations, and displays the reversed number. Error handling (e.g., for non-integer input) is omitted in this simplified example.

C# Code

using System;

public class ReverseNumberExample {
    public static void Main(string[] args) {
        Console.Write("Enter an integer: ");
        int number = int.Parse(Console.ReadLine());
        int reversedNumber = Reverse(number);
        Console.WriteLine($"Reversed number: {reversedNumber}");
    }

    public static int Reverse(int num) {
        int reversed = 0;
        while (num > 0) {
            int remainder = num % 10;
            reversed = (reversed * 10) + remainder;
            num /= 10;
        }
        return reversed;
    }
}

Conclusion

This program provides a concise solution for reversing integers in C#. The `Reverse` function efficiently reverses the number using simple arithmetic operations. Adding input validation would improve this program's robustness.