10. Price Change Alert

using System;

class PriceChangeAlert
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        double threshold = double.Parse(Console.ReadLine());
        double last = double.Parse(Console.ReadLine());
        for (int i = 0; i < n - 1; i++)
        {
            double price = double.Parse(Console.ReadLine());
            double diff = Proc(last, price);
            bool isSignificantDifference = isDiff(diff, threshold);
            string message = Get(price, last, diff, isSignificantDifference);
            Console.WriteLine(message);
            last = price;
        }
    }
    private static string Get(double price, double last, double change, bool etherTrueOrFalse)
    {
        string result = "";
        if (change == 0)
        {
            result = string.Format("NO CHANGE: {0}", price);
        }
        else if (!etherTrueOrFalse)
        {
            result = string.Format("MINOR CHANGE: {0} to {1} ({2:F2}%)", last, price, change * 100);
        }
        else if (etherTrueOrFalse && (change > 0))
        {
            result = string.Format("PRICE UP: {0} to {1} ({2:F2}%)", last, price, change * 100);
        }
        else if (etherTrueOrFalse && (change < 0))
            result = string.Format("PRICE DOWN: {0} to {1} ({2:F2}%)", last, price, change * 100);
        return result;
    }

    private static bool isDiff(double threshold, double isDiff)
    {
        if (Math.Abs(threshold) >= isDiff)
        {
            return true;
        }
        return false;
    }

    private static double Proc(double last, double price)
    {
        double res = (price - last) / last;
        return res;
    }
}