How to find if the number is a Perfect Square

What is a Perfect Square?

A Perfect square is a whole number which is produced by multiplying two equal integers. In other words, a number which has a square root as an integer is called a Perfect square.

Examples are 1, 4, 9, 25, .. and such.

How to find if the given number is a Perfect Square

This can be implemented in two ways: one by looping till half the number and checking if at each iteration multiplying the counter with itself results in the number.

public class CodingProblemSolution
{
    public static bool IsPerfectSquare(int n)
    {
        for (int i = 1; i <= n / 2; i++)
        {
            if (i * i == n)
            {
                return true;
            }
        }


        return false;
    }
}

This approach is similar to how we can find all the possible prime factors for all the numbers till the given limit

We can also approach this by using the Math library and finding the square root of the number. Then see if the obtained square root is an integer or not.

public class CodingProblemSolution
{
    public static bool IsPerfectSquareBySqRoot(int n)
    {
        double root = Math.Sqrt(n);

        if (root - Math.Floor(root) == 0)
        {
            return true;
        }

        return false;
    }
}