Problem 13.* Comparing Floats

namespace _13.ComparingFloats
{
    using System;
    /*
     * Write a program that safely compares floating-point numbers (double) with precision eps = 0.000001. Note that we cannot directly compare two floating-point numbers a and b by a==b because of the nature of the floating-point arithmetic. Therefore, we assume two numbers are equal if they are more closely to each other than a fixed constant eps. Examples:
        Number a    Number b    Equal (with precision eps=0.000001) Explanation
        5.3 6.01    false               The difference of 0.71 is too big (> eps)
        5.00000001  5.00000003  true    The difference 0.00000002 < eps
        5.00000005  5.00000001  true    The difference 0.00000004 < eps
        -0.0000007  0.00000007  true    The difference 0.00000077 < eps
        -4.999999   -4.999998   false   Border case. The difference 0.000001 == eps. We consider the numbers are different.
        4.999999    4.999998    false   Border case. The difference 0.000001 == eps. We consider the numbers are different.
     */
    class ComparingFloats
    {
        static void Main()
        {
            Console.Write("Enter first number : ");
            double firstNumber = double.Parse(Console.ReadLine());

            Console.Write("Enter second number : ");
            double secondNumber = double.Parse(Console.ReadLine());

            double difference = Math.Abs(firstNumber - secondNumber);

            double threshold = 0.000001; // doubles are equal if their difference is less than this value - you choose this value based on your needs
            bool areEqual = difference < threshold;

            Console.WriteLine(areEqual);
        }
    }
}