C#: Square root of a given number

Last update on June 24 2025 12:57:22 (UTC/GMT +8 hours)

Square Root Without Built-In Functions

Write a C# Sharp program to calculate the square root of a given number. Return the integer part of the result instead of using any built-in functions.

Sample Data:
(120) -> 10
(225) -> 15
(335) -> 18

Sample Solution:

C# Sharp Code:

using System;

namespace exercises
{
    class Program
    {
        static void Main(string[] args)
        {
            // Initializing integer 'n' with various values
            int n = 120;
            Console.WriteLine("Original number: " + n);

            // Displaying the square root of 'n'
            Console.WriteLine("Square root of the said number: " + test(n));

            // Changing the value of 'n' and repeating the process
            n = 225;
            Console.WriteLine("\nOriginal number: " + n);
            Console.WriteLine("Square root of the said number: " + test(n));

            // Changing the value of 'n' and repeating the process
            n = 335;
            Console.WriteLine("\nOriginal number: " + n);
            Console.WriteLine("Square root of the said number: " + test(n));
        }

        // Method to calculate the square root of a given number 'n'
        public static int test(double n)
        {
            int sq = 1;

            // Loop to find the square root using an iterative approach
            while (sq < n / sq)
            {
                sq++;
            }

            // Checking if the square is greater than 'n/square'. If so, returns the square - 1
            if (sq > n / sq) 
                return sq - 1;
            return sq; // Returning the square root of 'n'
        }
    }
}

Sample Output:

Original number: 120
Square root of the said number: 10

Original number: 225
Square root of the said number: 15

Original number: 335
Square root of the said number: 18

Flowchart:

For more Practice: Solve these Related Problems:

Write a C# program to compute the floor value of the square root using binary search.
Write a C# program to calculate the square root of a number to 3 decimal places using Newton's method.
Write a C# program to return the integer square root only if the input is a perfect square; else return -1.
Write a C# program to find the square root of a number by iterative subtraction of odd numbers.

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C# Sharp Code Editor: