[ BOJ/C# ] 1475 방 번호

https://www.acmicpc.net/problem/1475

1475번: 방 번호

using System;
using System.IO;

namespace B1475
{
    class Program
    {
        static void Main()
        {
            StreamReader sr = new StreamReader(Console.OpenStandardInput());
            StreamWriter sw = new StreamWriter(Console.OpenStandardOutput());

            int n = int.Parse(sr.ReadLine());
            int[] arr = new int[10];
            int set = 1;

            while (n > 0)
            {
                int m = n % 10;
                if (arr[m] == set)
                {
                    if (m == 6 && arr[9] < set) arr[9]++;
                    else if (m == 9 && arr[6] < set) arr[6]++;
                    else
                    {
                        arr[m]++;
                        set++;
                    }
                }
                else arr[m]++;
                n /= 10;
            }
            sw.Write(set);
            sr.Close();
            sw.Flush();
            sw.Close();
        }
    }
}