BrainFuck下的HappyNewYear

今天看了下一個語言叫BrainFuck，寫了個打印「Happy New Year!」的程序

（今天是2015年1月1日，順便祝你們新年快樂哈）

1.寫在前面

BrainFuck的主頁在： http://www.muppetlabs.com/~breadbox/bf/

我找了個BrainFuck代碼解釋器，能夠在Win7下運行，看圖標應該是VB6.0寫的，下載地址在：

http://esoteric.sange.fi/brainfuck/compiled/win/BFI.exe

BrainFuck的語法規則和簡易教程能夠參考英文維基百科的頁面：

https://en.wikipedia.org/wiki/Brainfuck

下面這個表就摘自這個維基百科頁面，BrainFuck由這些字符構成

命令（BrainFuck Command）	等價的C語句（C Equivalent）
程序開始（Program Start）	char array[無窮大] = { 0 }; char *ptr = array;
>	++ptr;
<	--ptr;
+	++*ptr;
-	--*ptr;
.	putchar(*ptr);
,	*ptr = getchar();
[	while(*ptr) {
]	}

2.程序代碼

1）縮進版本的代碼

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

>>.>---.>..+++++++++.<<<.<
>>++++++.>++++.>--.<<<.<
>>+++++++++++.>.----.>-----.<<<+.

BrainFuck的輸出理念，就是你能夠申請若干個空間，經過「>」和「<」在申請到的空間按申請的前後順序遍歷，用「+」和「-」能夠把改空間的值增1或減1，用「[」和「]」能夠指定一個循環節，這個循環在當前所處空間值爲0的時候結束，全部空間，初始值都是0，用「>」第一次移動到它的身上時就可使用了。一個空間的值能夠用「.」輸出該值做爲ASCII碼時所對應的字符（還有個「,」字符用於輸入，不過本段代碼中並無用到）

2）不縮進版本的代碼

BrainFuck不強制要求縮進，全部的字符能夠寫到同一行，下面這段代碼和1）中的效果同樣：

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

運行結果以下圖：

能夠看到，輸出了字符「Happy New Year!」

3.經過VBS腳本批量生成此類程序

一個用於輸出字符的BrainFuck，若是要作得簡短，須要在以前進行一些手工的計算

若是不考慮程序的長短，那麼批量生成就變得簡單得多

下面這個VBS腳本，能夠從一個寫有字符串的文本文件input.txt讀取信息，輸出到另外一個文本文件output.txt中

輸出的output.txt中保存着大量相似「>+++...(輸入字符對應ASCII碼數量個+)...+++.」的代碼段

Option Explicit

'讀取文件input.txt保存到InputString
Dim FSO : Set FSO = CreateObject("Scripting.FileSystemObject")
Dim FRead : Set FRead = FSO.OpenTextFile("input.txt", 1)
Dim InputString : InputString = FRead.ReadAll
FRead.Close

Dim OutputString 

'逐字比對，生成對應BrainFuck代碼
Dim i : For i = 1 to len(InputString)

    Dim TempChar : TempChar = mid(InputString, i, 1)    
    OutputString = OutputString & ">"
    Dim j : For j = 0 To Asc(TempChar) - 1
        OutputString = OutputString & "+"
    Next
    OutputString = OutputString & "." & VbCrLf

Next

'將OutputString的內容寫入到文件output.txt
Dim FWrite : Set FWrite = FSO.OpenTextFile("output.txt", 2, 1)
FWrite.Write OutputString
FWrite.Close

WScript.Echo "操做完畢"

如今假設input.txt中保存了一個字符串「Hello World!」

執行完上面這段VBS腳本後，生成的output.txt中會有下面的文字：

>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
>+++++++++++++++++++++++++++++++++.

把這段代碼放入代碼解釋器中，也能獲得「Happy New Year!」的輸出，就是不如以前手算的代碼簡潔罷了 ：-）

END