Number Series Codes using C#

Introduction 

 

This article will help you learn and write code on some famous number series. For demonstration purposes, I used Visual Studio Code for the C# code.

 

To set up the environment for C# in Visual Studio Code, refer here.

 

Check even or odd number 

public void OddEvenNumber()
{
    // Number which is divisible by 2 is known as Even number
    // Number which is not divisible by 2 is known as Odd number
    Console.Write("Enter the number: ");
    int number = Convert.ToInt32(Console.ReadLine());
    if (number % 2 == 0) // check number after division is zero
    {
        Console.Write(number + " is Even Number"); // If divisible by number
    }
    else
    {
        Console.Write(number + " is Odd number"); // if not divisble by number
    }
}

Output

 

 

 

Check Prime Number

public void PrimeNumber()
{
    // Prime numbers are numbers divisible by 1 and itself.
    Console.Write("Enter the number: ");
    int number = Convert.ToInt32(Console.ReadLine());
    int i, m = 0, count = 0;
    m =  number / 2;
    for (i = 2; i <= m; i++) // check number is divisible by any another number
    {
        if (number % i == 0) // If number is divisible by another number
        {
            count = 1; // reassign the count to 1
            break; // break the for loop
        }
    }
    if (number > 1 && count == 0) // number should be greater than 1.
    {
        Console.Write(number + " is prime number");
    }
    else
    {
        Console.Write(number + " is non prime number");
    }
}

Output

 

 

 
Print prime number from 1 to 100

public void PrintPrimeNumber1To100()
{
    // Prime number are the number which is divisible by 1 or itself.
    bool isPrimeNumber = true; // check number is prime number
    int outerloop, innerloop; // declare to
    Console.WriteLine("Prime Numbers are : ");
    for (outerloop = 2; outerloop <= 100; outerloop++)
    {
        for (innerloop= 2; innerloop <= 100; innerloop++)
        {
            if (outerloop != innerloop && outerloop % innerloop== 0)
            {
                isPrimeNumber = false;
                break;
            }
        }
        if (isPrimeNumber) // If number is prime number print them on console.
        {
            Console.Write("\t" + outerloop);
        }
        isPrimeNumber = true;
    }
    Console.ReadLine();
}

 Output

 

 

 

Print factorial of input number

public void Factorial()
{
    // Factorial of number 4 is: 4*3*2*1 = 24
    int num, factorial = 1;
    Console.Write("Enter the number: ");
    num = Convert.ToInt32(Console.ReadLine());
    while (num >= 1) // check number is greater or equal to 1
    {
        factorial = factorial * num; // multiply the number
        num--; // decrement the number by 1
    }
    Console.Write("Factorial: " + factorial);
}

Output

 

 

Print the reverse number of input number    

public void ReverseNumber()
{
    // ReverseNumber
    int originalNumber, reverseNumber = 0;
    Console.Write("Enter the number: ");
    originalNumber = Convert.ToInt32(Console.ReadLine());
    while (originalNumber >= 1)
    {
        reverseNumber = reverseNumber * 10 + originalNumber % 10; // multiply the reverseNumber with 10 and modulus on orginal number
        originalNumber = originalNumber / 10;
    }
    Console.Write("Reverse Number: " + reverseNumber);
}

Output

 

 

  

Check if input number is palidrome or not

public void CheckPalidromeNumber()
{
    // Palidrome number is number that remains same when its digit are reversed.
    int numb, temp = 0, orginalNumb;
    Console.Write("Enter the number: ");
    numb = Convert.ToInt32(Console.ReadLine());
    orginalNumb = numb; // store the entered number into original number
    while (numb >= 1)
    {
        temp = temp * 10 + numb % 10;
        numb = numb / 10;
    }
    if (temp == orginalNumb) // check orginal number and temp are same.
    {
        Console.Write("Palidrome Number");
    }
    else
    {
        Console.Write("Not a Palidrome Number");
    }
}

Output

 

 

Addition of input numbers 

public void SumOfNumber()
{
    // sum of number => adding all the digits
    int num, sum = 0;
    Console.Write("Enter the number: ");
    num = Convert.ToInt32(Console.ReadLine());
    while (num >= 1)
    {
        sum = sum + num % 10;
        num = num / 10;
    }
    Console.Write("Sum of Number: " + sum);
}

Output

 

 

 

Print the greatest common divisor (GCD) between two numbers

public void GCDNumber()
{
    // GCD Number are known as Greatest Common Divisor
    // number which is the largest number that divides both number
    // Example
    // 3 = 3
    // 6 = 2 * 3
    // So the GCD of 3 and 6 is: 3
    int num1, num2;
    Console.Write("Enter the First number: ");
    num1 = Convert.ToInt32(Console.ReadLine());
    Console.Write("Enter the second number: ");
    num2 = Convert.ToInt32(Console.ReadLine());
    while (num1 != num2) // numb1 not equal to num2
    {
        if (num1 > num2) // check num1 is greater than num2
        {
            num1 = num1 - num2; // subtract num2 form num1
        }
        else
        {
            num2 = num2 - num1; // else subtract num1 from num2
        }
    }
    if (num1 == 1)
    {
        Console.Write("No GCD Number");
    }
    else
    {
        Console.Write("GCD Number: " + num1);
    }
}

Output

 

 

 

Print the least common multiplier (LCM) between two numbers

public void LCMNumber()
{
    // LCM Number are Least Common Multiplication
    // LCM of two number is the smallest number (not zero) that is a multiple of both.
    // 6 = 2 * 3
    // 8 = 2 * 2 * 2
    // So the GCD of 6 and 8 is: 24
    int num1, num2, a, b, lcmNum;
    Console.Write("Enter the First number: ");
    num1 = Convert.ToInt32(Console.ReadLine());
    Console.Write("Enter the second number: ");
    num2 = Convert.ToInt32(Console.ReadLine());
    a = num2;
    b = num1;
    while (num1 != num2) // check num1 is equal or not
    {
        if (num1 > num2) // check num1 is greater than num2
        {
            num1 = num1 - num2; // subtract num2 from num1 and save in num1
        }
        else
        {
            num2 = num2 - num1; // subtract num1 from num2 and save in num2
        }
    }
    lcmNum = (a * b) / num1; // multiply the orinal two number and divide with num1
    Console.Write("LCM number: " + lcmNum);
}

Output

 

 

 

Print table from 1 to 10

public void print1To10Table()
{
    // Print table form 1 to 10
    for (int num1 = 1; num1 <= 10; num1++)
    {
        for (int num2 = 1; num2 <= 10; num2++)
        {
            Console.Write(num1 * num2 + "\t");
        }
        Console.WriteLine("");
    }
}

Output

 

 

 

Fibonacci Series of input numbers

public void FibonacciNumber()
{
    // Fibonacci Series till number 10 is:  0, 1, 1, 2, 3, 5, 8, 13, 21, 34
    int num, firstNum = 0, secondNum = 1, temp, thirdNum = 3;
    Console.Write("Enter the number: ");
    num = Convert.ToInt32(Console.ReadLine());
    Console.Write(firstNum + "\t" + secondNum); // print the first two number i.e 1 2
    while (thirdNum <= num) // check enter number is less than third number i.e 3
    {
        temp = firstNum + secondNum; // add firstNum and secondNum and stored in temp
        Console.Write("\t" + temp); // print the third numb
        firstNum = secondNum; // assing secondNumb to firstNum
        secondNum = temp; // assing temp number to secondNum
        thirdNum = thirdNum + 1; // Increment the thirdNum
    }
}

Output

 

 

 

Swap numbers using a third variable

public void SwapNumber()
{
    // Swap Number
    // Orginal Number: x = 2 and y = 3
    // After Swapping: x = 3 and y = 2
    // This method will swap number using temp variable
    int num1, num2, temp;
    Console.Write("Enter the First number: ");
    num1 = Convert.ToInt32(Console.ReadLine());
    Console.Write("Enter the second number: ");
    num2 = Convert.ToInt32(Console.ReadLine());
    Console.WriteLine("Number Before Swap x: " + num1 + " y: " + num2);
    temp = num2; // assign the second number to temp
    num2 = num1; // assign the first number to second number
    num1 = temp; // assign temp to second number
    Console.WriteLine("Number After Swap x: " + num1 + " y: " + num2);
}

Output

 

 

 

Swap number without using a third variable

public void SwapNumberWithoutThirdVariable()
{
    int num1, num2;
    Console.Write("Enter the First number: ");
    num1 = Convert.ToInt32(Console.ReadLine());
    Console.Write("Enter the second number: ");
    num2 = Convert.ToInt32(Console.ReadLine());
    Console.WriteLine("Number Before Swap x: " + num1 + " y: " + num2);
    num1 = num1 + num2; // add num1 and num2
    num2 = num1 - num2; // subtract num2 from num1 and assign to num2
    num1 = num1 - num2; // subtract num2 form num1 and assign to num1
    Console.WriteLine("Number After Swap x: " + num1 + " y: " + num2);
}

Output

 

 

 

Print tranpose of a 3 by 3 matrix 

public void Print3By3MatrixTranspose()
{
    // The transpose of a matrix is a new matrix whose rows are the columns of the original.
    int[,] pos = new int[3, 3]; // declare multidimensional array which accepts 3 rows by 3 columns
    int rows, cols; // initialize rows and columns
    Console.WriteLine("Enter value for Matrix:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            pos[rows, cols] = Convert.ToInt32(Console.ReadLine()); // read the 9 digit in the matrix
        }
    }
    Console.WriteLine("Original Matrix:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            Console.Write(pos[rows, cols] + "\t"); // print the original matrix
        }
        Console.WriteLine("");
    }
    Console.WriteLine("Transpose of  Matrix:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            Console.Write(pos[cols, rows] + "\t");  // change the row to column
        }
        Console.WriteLine("");
    }
}

Output

  

 

 

Matrix multiplication between two 3 by 3 matrices

public void Print3By3MatrixMultiplication()
{
    /*
    * Step 1: Make sure that the the number of columns in the 1st one equals the number of rows in the 2nd one. (The pre-requisite to be able to multiply)
    * Step 2: Multiply the elements of each row of the first matrix by the elements of each column in the second matrix.
    * Step 3: Add the products.
    *
    * Example: Below matrix will be denoted as per following symbols
    *
    * FirstMatrix = fm
    * SecondMatrix = sm
    * ResultMatrix  = rm
    *
    * rm[0,0] = fm[0,0]*sm[0,0] + fm[0,1]*sm[1,0] + fm[0,3]*sm[2,0]
    * rm[0,1] = fm[0,0]*sm[0,1] + fm[0,1]*sm[1,1] + fm[0,0]*sm[2,1]
    * rm[0,2] = fm[0,0]*sm[0,2] + fm[0,1]*sm[1,2] + fm[0,0]*sm[2,2]
    * *
    * *
    * *
    * rm[2,2] = fm[2,0]*sm[0,2] + fm[2,1]*sm[1,2] + fm[2,2]*sm[2,2]
    */

    // declare 3 multidimensional array
    int[,] fm = new int[3, 3];
    int[,] sm = new int[3, 3];
    int[,] rm = new int[3, 3];
    int rows, cols, temp, rowTemp;
    Console.WriteLine("Enter value for Matrix 1: ");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            fm[rows, cols] = Convert.ToInt32(Console.ReadLine()); // Read first matrix value and store into fm array
        }
    }
    Console.WriteLine("Enter value for Matrix 2: ");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            sm[rows, cols] = Convert.ToInt32(Console.ReadLine()); // Read secnd matrix value and store into sm
        }
    }
    Console.WriteLine("Original Matrix 1:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            Console.Write(fm[rows, cols] + "\t"); // Print first matrix
        }
        Console.WriteLine("");
    }
    Console.WriteLine("Original Matrix 2:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            Console.Write(sm[rows, cols] + "\t"); // print second matrix
        }
        Console.WriteLine("");
    }

    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            for (rowTemp = 0, temp = 0; temp < 3; temp++)
            {
                rowTemp = rowTemp + fm[rows, temp] * sm[temp, cols]; // fm[0,0]*sm[0,0] + fm[0,1]*sm[1,0] + fm[0,3]*sm[2,0]
            }
            rm[rows, cols] = rowTemp;// rm[0,0] = rowTemp
        }
    }
    Console.WriteLine("Multiplication of 2 Matrix is:");
    for (rows = 0; rows < 3; rows++)
    {
        for (cols = 0; cols < 3; cols++)
        {
            Console.Write(rm[rows, cols] + "\t"); // Print the result matrix.
        }
        Console.WriteLine("");
    }

}

Output

 

 

Triangle number pyramid

 

Print the number pyramid which looks like following,

 

    1

  2  2

3 3  3 

public void TrianglePyramidNumber()
{
    // print the Triangle pyaramid for 9 digit
    int rows, cols, temp, space = 8;
    for (rows = 1; rows <= 9; rows++)
    {
        for (cols = space; cols >= 1; cols--)
        {
            Console.Write(" "); // print space
        }
        for (temp = 1; temp <= rows; temp++)
        {
            Console.Write(rows + " "); // print rows value
        }
        Console.WriteLine("");
        space--;
    }
}

Output

 

 

 

Print the number pyramid where the numbers start from the left side.

public void leftPyramidNumber()
{
    // Start the pyramid from left side.
    int rows, cols;
    for (rows = 1; rows <= 9; rows++)
    {
        for (cols = 1; cols <= rows; cols++)
        {
            Console.Write(rows + " "); // print rows value
        }
        Console.WriteLine("");
    }
}

Output

 

 

Print the number pyramid where numbers start from the right side.  

public void RightPyramidNumber()
{
    // start the pyramid from right side
    int rows, cols;
    for (rows = 1; rows <= 9; rows++)
    {
        for (cols = 1; cols <= 9 - rows; cols++)
        {
            Console.Write("\t"); // print number of space row - 1  = 9-1 => 8
        }
        for (cols = 1; cols <= rows; cols++)
        {
            Console.Write(rows + "\t"); // print rows value.
        }
        Console.WriteLine("");
    }

}

Output

 

 

 

 Find the source code as an attachment.