zad 401

class Program
    {
        static void Main(string[] args)
        {
            int n;

            do
            {
                Console.Write("Enter n: ");
                n = int.Parse(Console.ReadLine());
            } while (n > 31 || n <= 0);
            Console.WriteLine();

            double[] A, B, C;
            Console.WriteLine("For station A:\n");
            A = enterValues(n);

            Console.WriteLine("For station B:\n");
            B = enterValues(n);

            Console.WriteLine("For station C:\n");
            C = enterValues(n);

            Console.WriteLine();

            //a
            Console.Write("Average values for station A:\n{0:0.00} => ", findAvrgValueForMonth(A));
            Console.WriteLine();

            //b
            Console.Write("Average values for station B:\n{0:0.00} => ", findAvrgValueForMonth(B));
            Console.WriteLine();

            //c
            Console.Write("Average values for station C:\n{0:0.00} => ", findAvrgValueForMonth(C));
            Console.WriteLine();
        }

        static double findAvrgValueForMonth(double[] month)
        {
            double sum = 0;
            int counter = 0;
            for (int i = 0; i < month.Length; i++)
            {
                if (month[i] > 0)
                {
                    sum += month[i];
                    counter++;
                }
            }

            return sum/counter;
        }

        static double[] enterValues(int n)
        {
            double[] days = new double[n];
            for (int i = 0; i < n; i++)
            {
                enterValue:
                Console.Write("Enter liters for m2 for day {0}: ", i + 1);
                days[i] = double.Parse(Console.ReadLine());
                if (days[i] < 0)
                {
                    Console.WriteLine("You can't enter negative value!");
                    goto enterValue;
                }
            }

            return days;
        }
    }