완주하지 못한 선수

programmers.co.kr/learn/courses/30/lessons/42576

코딩테스트 연습 - 완주하지 못한 선수

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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] participant = { "john", "ed", "joe", "rick", "john" };
            string[] completed = { "john", "ed", "joe", "john" };

            Dictionary<string, int> dic = new Dictionary<string, int>();

            foreach (var name in completed) {
                if (!dic.ContainsKey(name)) {
                    dic.Add(name, 1);
                }
            }

            string answer = "";
            foreach (var name in participant)
            {
                if (dic.ContainsKey(name))
                {
                    dic[name] -= 1;
                }
                else {
                    answer = name;
                    break;
                }

                if (dic[name] < 0)
                {
                    answer = name;
                    break;
                }
            }

            Console.WriteLine("------------------->" + answer);

        }
    }
}