Яндекс.Блиц. A

A_Game.cs

// https://contest.yandex.ru/hiring/contest/5048/problems/A/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yandex.blitz
{
    public class A_Game
    {
        public enum IO_Type { FILE, CONSOLE };
        public static IO_Type ioType = IO_Type.CONSOLE;
        public static readonly string petyaName = "Petya";
        public static readonly string vasyaName = "Vasya";

        public static void Main(string[] args)
        {
            HashSet<int> petya;
            HashSet<int> vasya;

            LoadFromInput(out petya, out vasya);

            int petyaSum = petya.Sum();
            int vasyaSum = vasya.Sum();

            CalcWinner(petya, vasya, petyaSum, vasyaSum);
        }

        static bool LoadFromFile(string fname, out HashSet<int> petya, out HashSet<int> vasya)
        {
            using (var file = new System.IO.StreamReader(fname))
            {
                var firstLine = file.ReadLine();
                var secondLine = file.ReadLine();

                LoadData(firstLine, secondLine, out petya, out vasya);

                return true;
            }
        }

        static bool LoadFromInput(out HashSet<int> petya, out HashSet<int> vasya)
        {
            var firstLine = System.Console.ReadLine();
            var secondLine = System.Console.ReadLine();

            LoadData(firstLine, secondLine, out petya, out vasya);

            return true;
        }

        static bool LoadData(string firstLine, string secondLine, out HashSet<int> petya, out HashSet<int> vasya)
        {
            int n;
            petya = new HashSet<int>();
            vasya = new HashSet<int>();

            if (!int.TryParse(firstLine, out n))
            {
                return false;
            }
            if (n < 2 || n > 1000)
            {
                return false;
            }

            var values = secondLine.Split(' ');
            for (int i = 0; i < values.Length; i += 2)
            {
                int odd = int.Parse(values[i]);
                int even = int.Parse(values[i + 1]);
                petya.Add(odd);
                vasya.Add(even);
            }

            return true;
        }

        static void PrintWinner(string winner)
        {
            switch (ioType)
            {
                case IO_Type.CONSOLE:
                    Console.WriteLine(winner);
                    break;
                case IO_Type.FILE:
                    using (var file = new System.IO.StreamWriter("output.txt"))
                    {
                        file.WriteLine(winner);
                    }
                    break;
            }
        }

        static void CalcWinner(HashSet<int> petya, HashSet<int> vasya, int petyaVal, int vasyaVal)
        {
            if (petyaVal > vasyaVal)
            {
                PrintWinner(petyaName);
            }
            else if (petyaVal < vasyaVal)
            {
                PrintWinner(vasyaName);
            }
            else if (0 == petya.Count || 0 == vasya.Count)
            {
                PrintWinner(petyaName);
            }
            else
            {
                petyaVal = petya.Max(); petya.Remove(petyaVal);
                vasyaVal = vasya.Max(); vasya.Remove(vasyaVal);
                CalcWinner(petya, vasya, petyaVal, vasyaVal);
            }

        }
    }
}