Kattio.cs

using System;
using System.IO;

namespace Kattis.IO
{
	public class NoMoreTokensException : Exception
	{
	}

	public class Tokenizer
	{
		string[] tokens = new string[0];
	    private int pos;
		StreamReader reader;

	    public Tokenizer(Stream inStream)
		{
			var bs = new BufferedStream(inStream);
			reader = new StreamReader(bs);
		}

		public Tokenizer() : this(Console.OpenStandardInput())
		{
			// Nothing more to do
		}

		private string PeekNext()
		{
		    if (pos < 0)
				// pos < 0 indicates that there are no more tokens
				return null;
		    if (pos < tokens.Length)
		    {
		        if (tokens[pos].Length == 0)
		        {
		            ++pos;
		            return PeekNext();
		        }
		        return tokens[pos];
		    }
	        string line = reader.ReadLine();
	        if (line == null)
	        {
                // There is no more data to read
                pos = -1;
	            return null;
	        }
            // Split the line that was read on white space characters
		    tokens = line.Split(null);
		    pos = 0;
            return PeekNext();
		}

	    public bool HasNext()
		{
			return (PeekNext() != null);
		}

		public string Next()
		{
			string next = PeekNext();
			if (next == null)
				throw new NoMoreTokensException();
			++pos;
			return next;
		}
	}


	public class Scanner : Tokenizer
	{

		public int NextInt()
		{
			return int.Parse(Next());
		}

		public long NextLong()
		{
			return long.Parse(Next());
		}

		public float NextFloat()
		{
			return float.Parse(Next());
		}

		public double NextDouble()
		{
			return double.Parse(Next());
		}
	}


	public class BufferedStdoutWriter : StreamWriter
	{
		public BufferedStdoutWriter() : base(new BufferedStream(Console.OpenStandardOutput()))
		{
		}
	}

}