FinalExamPrepare/ConsoleAppForLibrary/FirstLibrary/WorkPaymentCalculator.cs

using System;
using System.Collections.Generic;

namespace FirstLibrary
{
    public class WorkPaymentCalculator
    {
        public class WorkDay
        {
            public DateTime Date { get; set; }
            public int HourCount { get; set; }
        }


        public static double CalculateSalary(double hourSalary, List<WorkDay> workDays, int experience)
        {
            double salary = 0;
            double kExperience = (experience < 5)? 1d : (experience >= 5 && experience < 10)? 1.1d : 1.2d;

            foreach (WorkDay workDay in workDays) 
            {
                double daySalary = 0;
                bool isHolyday = workDay.Date.DayOfWeek == DayOfWeek.Sunday || workDay.Date.DayOfWeek == DayOfWeek.Saturday;
                if(workDay.HourCount > 8)
                    daySalary = 8 * hourSalary * (isHolyday ? 2 : 1) + (workDay.HourCount - 8) * hourSalary * 2 * (isHolyday ? 2 : 1);
                else 
                    daySalary = workDay.HourCount * hourSalary * (isHolyday ? 2 : 1);
                salary += daySalary;
            }

            return salary * kExperience;
        }
    }
}