C#でbrainfuck

C#の練習で実装

brainfuckとは http://dic.nicovideo.jp/a/brainfuck

一部機能は実装してないが、Hello World!出力できたのでよし

入力

+++++++++[>++++++++>+++++++++++>+++++<<<-]>.>++.+++++++..+++.>-.------------.<++++++++.--------.+++.------.--------.>+.

出力

Hello, world!

コード

brainfuck.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace brainfuck
{
    class BrainFuck
    {
        static int search1(string str, int start)
        {
            int c = 0;
            for (int i = start + 1; i < str.Length; ++i)
            {
                if (str[i] == '[')
                {
                    c++;
                }
                if (str[i] == ']')
                {
                    if (c == 0)
                    {
                        return i;
                    }
                    else
                    {
                        c--;
                    }
                }
            }
            return -1;
        }

        static int search2(string str, int start)
        {
            int c = 0;
            string rev = new string(str.Reverse().ToArray());
            int rev_start = str.Length - start - 1;
            for (int i = rev_start + 1; i < rev.Length; ++i)
            {
                if (rev[i] == ']')
                {
                    c++;
                }
                if (rev[i] == '[')
                {
                    if (c == 0)
                    {
                        return str.Length - i - 1;
                    }
                    else
                    {
                        c--;
                    }
                }
            }
            return -1;
        }

        public static void Main(string[] args)
        {
            int[] memory = new int[3000];
            int address = 0;
            string str = "+++++++++[>++++++++>+++++++++++>+++++<<<-]>.>++.+++++++..+++.>-.------------.<++++++++.--------.+++.------.--------.>+.";
            for (int i = 0; i < str.Length; i++)
            {
                switch (str[i])
                {
                    case '>':
                        address++;
                        break;
                    case '<':
                        address--;
                        break;
                    case '.':
                        Console.Write((char)memory[address]);
                        break;
                    case '+':
                        memory[address]++;
                        break;
                    case '-':
                        memory[address]--;
                        break;
                    case '[':
                        if (memory[address] == 0)
                        {
                            i = search1(str, i);
                        }
                        break;
                    case ']':
                        if (memory[address] != 0)
                        {
                            i = search2(str, i);
                        }
                        break;
                }
            }
        }
    }
}