C# Program to find Number Combination

Posted in C# Tutorial

Updated on Oct 27, 2024

By Mari Selvan

👁️ 427 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, creating combinations of numbers is a common and useful task. A combination is a selection of items from a collection, where the order of selection does not matter.

In this tutorial, we'll explore a C# program that generates combinations of two specified numbers within a given range.

📄 Example

Let's take a look at the C# code that achieves this functionality.

Program.cs

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using System;

class Program {
  // Function to calculate the number of digits in a number
  static int CountDigits(int num) {
    int count = 0;
    while (num != 0) {
      num /= 10;
      ++count;
    }
    return count;
  }

  // Function to generate combinations of two numbers up to a specified limit
  static void GenerateCombinations(int number1, int number2, int limit) {
    Console.Write($"List of combinations of {number1} and {number2} up to {limit}:\n");

    for (int i = 1; i <= limit; ++i) {
      int currentNumber = i;

      // Check if the current number contains only the specified digits
      while (currentNumber > 0) {
        int digit = currentNumber % 10;
        if (digit != number1 && digit != number2) {
          break;
        }
        currentNumber /= 10;
      }

      // If the current number contains only the specified digits, print it
      if (currentNumber == 0) {
        Console.Write($"{i} ");
      }
    }

    Console.WriteLine();
  }

  // Driver program
  static void Main() {
    // Replace these values with your desired numbers and limit
    int targetNumber1 = 4;
    int targetNumber2 = 8;
    int combinationLimit = 500;

    // Call the function to generate combinations
    GenerateCombinations(targetNumber1, targetNumber2, combinationLimit);
  }
}

💻 Testing the Program

To test the program with different values, replace the values of targetNumber1, targetNumber2, and combinationLimit in the Main method.

Output

List of combinations of 4 and 8 up to 500:
4 8 44 48 84 88 444 448 484 488

Compile and run the program to see the list of combinations.

🧠 How the Program Works

The program defines a function CountDigits to calculate the number of digits in a given number.
The function GenerateCombinations generates combinations of two specified numbers up to a given limit.
Inside the function, it iterates through numbers from 1 to the specified limit.
For each iteration, it checks if the current number contains only the specified digits.
If the coxdition is met, the current number is a combination, and it is printed.

🧐 Understanding the Concept of Number Combination

Before delving into the code, let's take a moment to understand the concept of combinations. In mathematics, a combination is a selection of items from a collection, where the order of selection does not matter.

For example, consider the specified numbers as 4 and 8. The combinations of 4 and 8 up to 500 include 4, 8, 44, 48, 84, 88, 444, 448, 484, and 488.