BrainFuck下的HappyNewYear

今天看了下一个语言叫BrainFuck，写了个打印“Happy New Year!”的程序

（今天是2015年1月1日，顺便祝你们新年快乐哈）

1.写在前面

BrainFuck的主页在： http://www.muppetlabs.com/~breadbox/bf/

我找了个BrainFuck代码解释器，能够在Win7下运行，看图标应该是VB6.0写的，下载地址在：

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

BrainFuck的语法规则和简易教程能够参考英文维基百科的页面：

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

下面这个表就摘自这个维基百科页面，BrainFuck由这些字符构成

命令（BrainFuck Command）	等价的C语句（C Equivalent）
程序开始（Program Start）	char array[无穷大] = { 0 }; char *ptr = array;
>	++ptr;
<	--ptr;
+	++*ptr;
-	--*ptr;
.	putchar(*ptr);
,	*ptr = getchar();
[	while(*ptr) {
]	}

2.程序代码

1）缩进版本的代码

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

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

BrainFuck的输出理念，就是你能够申请若干个空间，经过“>”和“<”在申请到的空间按申请的前后顺序遍历，用“+”和“-”能够把改空间的值增1或减1，用“[”和“]”能够指定一个循环节，这个循环在当前所处空间值为0的时候结束，全部空间，初始值都是0，用“>”第一次移动到它的身上时就可使用了。一个空间的值能够用“.”输出该值做为ASCII码时所对应的字符（还有个“,”字符用于输入，不过本段代码中并无用到）

2）不缩进版本的代码

BrainFuck不强制要求缩进，全部的字符能够写到同一行，下面这段代码和1）中的效果同样：

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

运行结果以下图：

能够看到，输出了字符“Happy New Year!”

3.经过VBS脚本批量生成此类程序

一个用于输出字符的BrainFuck，若是要作得简短，须要在以前进行一些手工的计算

若是不考虑程序的长短，那么批量生成就变得简单得多

下面这个VBS脚本，能够从一个写有字符串的文本文件input.txt读取信息，输出到另外一个文本文件output.txt中

输出的output.txt中保存着大量相似“>+++...(输入字符对应ASCII码数量个+)...+++.”的代码段

Option Explicit

'读取文件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 

'逐字比对，生成对应BrainFuck代码
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

'将OutputString的内容写入到文件output.txt
Dim FWrite : Set FWrite = FSO.OpenTextFile("output.txt", 2, 1)
FWrite.Write OutputString
FWrite.Close

WScript.Echo "操做完毕"

如今假设input.txt中保存了一个字符串“Hello World!”

执行完上面这段VBS脚本后，生成的output.txt中会有下面的文字：

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

把这段代码放入代码解释器中，也能获得“Happy New Year!”的输出，就是不如以前手算的代码简洁罢了 ：-）

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