C#: Calculate the sum of the series 1 +11 + 111 + 1111 + .. n terms

Last update on December 20 2024 12:50:03 (UTC/GMT +8 hours)

Write a program in C# Sharp to find the sum of the series 1 +11 + 111 + 1111 + .. n terms.

Visual Presentation:

Sample Solution:

C# Sharp Code:

using System;  // Importing necessary namespace

public class Exercise26  // Declaration of the Exercise26 class
{  
    public static void Main()  // Main method, entry point of the program
    {
        int n, i, sum = 0;  // Declaration of variables n, i, and sum as integers
        int t = 1;  // Initializing t as 1

        Console.Write("\n\n");  // Displaying new lines
        Console.Write("Calculate the sum of the series 1 +11 + 111 + 1111 + .. n terms:\n");  // Displaying the purpose of the program
        Console.Write("------------------------------------------------------------------");  // Displaying a separator
        Console.Write("\n\n");  // Displaying new lines

        Console.Write("Input the number of terms : ");  // Prompting the user to input the number of terms
        n = Convert.ToInt32(Console.ReadLine());  // Reading the number of terms entered by the user

        // Loop to generate the series and calculate its sum
        for (i = 1; i <= n; i++)
        {
            Console.Write("{0} + ", t);  // Displaying the current term in the series
            sum = sum + t;  // Calculating the sum of the series
            t = (t * 10) + 1;  // Generating the next term in the series
        }

        Console.Write("\nThe Sum is : {0}\n", sum);  // Displaying the total sum of the series
    }
}

Sample Output:

Calculate the sum of the series 1 +11 + 111 + 1111 + .. n terms:                                                                                               
------------------------------------------------------------------                                                                                             
Input the numbe of terms : 6                                                                                                         
1 + 11 + 111 + 1111 + 11111 + 111111 +                                                                                                         
The Sum is : 123456 

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