字符串中的第一个不同字符 [英] first different character in string

问题描述

有没有一种快速的方法可以找到第一个字符的索引不同的

两个字符串？


例如，如果我有字符串

" abcdefghijkl"

和

" abcdefxyz"

我希望返回值为6。


无论是在C＃还是C ++中。 （我显然知道如何通过循环遍历字符数组中的

字符来实现它，但我想知道是否有一些

smart-alec内存操作函数， asm甚至是正则表达式我可以使用

来做它。）


谢谢

Is there a quick way to find the index of the first character different in
two strings?

For instance, if I had the strings
"abcdefghijkl"
and
"abcdefxyz"
I would want the return value to be 6.

Either in C# or C++. (I obviously know how to do it by looping through the
characters in the character array, but I was wondering if there was some
smart-alec memory-manipulation function, asm even, or regexes I could use
that would do it.)

Thanks

推荐答案

在32位环境中，最快的方法是找到4字节的

边界，并开始一次读取和比较4个字节。如果发现不匹配

，你会挖掘并在字节/字级别比较它们（取决于是否

你的编码是8位还是16位）


在x86 asm中，你应该使用字符串优化的lodsb，cmpsb说明。


-vJ


" Beeeeeves" < 1234512345789123456789>在消息中写道

news：uy ****************** @ TK2MSFTNGP10.phx.gbl ...

In a 32 bit environment, the fastest approach would be find the 4-byte
boundary and start reading and comparing 4 bytes at a time. When a mismatch
is found, you''ll dig in and compare them at byte/word level (depending on if
your encoding is 8-bit or 16-bit)

In x86 asm, you should use the string optimized lodsb, cmpsb instructions.

-vJ

"Beeeeeves" <1234512345789123456789> wrote in message
news:uy******************@TK2MSFTNGP10.phx.gbl...

是有一个快速的方法来找到两个字符串中第一个字符的索引不同吗？

例如，如果我有字符串
" abcdefghijkl"

" abcdefxyz"
我希望返回值为6.

在C＃或C ++中。 （我显然知道如何通过循环遍历字符数组中的
字符来实现它，但我想知道是否有一些
smart-alec内存操作函数，甚至是asm，还是我可以使用的正则表达式
就可以了。）

谢谢

Is there a quick way to find the index of the first character different in
two strings?

For instance, if I had the strings
"abcdefghijkl"
and
"abcdefxyz"
I would want the return value to be 6.

Either in C# or C++. (I obviously know how to do it by looping through the
characters in the character array, but I was wondering if there was some
smart-alec memory-manipulation function, asm even, or regexes I could use
that would do it.)

Thanks

Vijaye Raji <无************* @ hotmail.com>在消息中写道

新闻：O3 ************* @ TK2MSFTNGP10.phx.gbl ...

"Vijaye Raji" <no*************@hotmail.com> wrote in message
news:O3*************@TK2MSFTNGP10.phx.gbl...

在32位环境中，最快的方法是找到4字节的边界，并开始一次读取和比较4个字节。当发现
不匹配时，你会挖掘并在字节/字级别比较它们（如果你的编码是8位或16位，则取决于
）


这就是我所采用的。

在x86 asm中，你应该使用字符串优化的lodsb，cmpsb指令。


知道任何例子吗？

-vJ

Beeeeeves < 1234512345789123456789>在消息中写道
新闻：uy ****************** @ TK2MSFTNGP10.phx.gbl ...

In a 32 bit environment, the fastest approach would be find the 4-byte
boundary and start reading and comparing 4 bytes at a time. When a mismatch is found, you''ll dig in and compare them at byte/word level (depending on if your encoding is 8-bit or 16-bit)
That''s what I''ve resorted to.

In x86 asm, you should use the string optimized lodsb, cmpsb instructions.
Know any examples?

-vJ

"Beeeeeves" <1234512345789123456789> wrote in message
news:uy******************@TK2MSFTNGP10.phx.gbl...

有没有快速的方法在两个字符串中找到不同
的第一个字符的索引？

例如，如果我有字符串
" abcdefghijkl"
和
abcdefxyz
我希望返回值为6.

在C＃或C ++中。 （我显然知道如何通过循环
字符数组中的字符来做到这一点，但我想知道是否有一些
smart-alec内存操作函数，asm甚至或正则表达式我可以
使用它会这样做。）

谢谢

Is there a quick way to find the index of the first character different in two strings?

For instance, if I had the strings
"abcdefghijkl"
and
"abcdefxyz"
I would want the return value to be 6.

Either in C# or C++. (I obviously know how to do it by looping through the characters in the character array, but I was wondering if there was some
smart-alec memory-manipulation function, asm even, or regexes I could use that would do it.)

Thanks

来吧，你知道你想要的。我很想在这个程序中得到一些汇编语言

;-)


" Vijaye Raji" <无************* @ hotmail.com>在消息中写道

新闻：O3 ************* @ TK2MSFTNGP10.phx.gbl ...

Come on, you know you want to. I''d love to get a bit of assembly language
into this program ;-)

"Vijaye Raji" <no*************@hotmail.com> wrote in message
news:O3*************@TK2MSFTNGP10.phx.gbl...

在32位环境中，最快的方法是找到4字节的边界，并开始一次读取和比较4个字节。当找到
不匹配时，你会挖掘并在字节/字级别比较它们（如果你的编码是8位或16位，则取决于
）

>在x86 asm中，你应该使用字符串优化的lodsb，cmpsb指令。

-vJ

" Beeeeeves" < 1234512345789123456789>在消息中写道
新闻：uy ****************** @ TK2MSFTNGP10.phx.gbl ...

In a 32 bit environment, the fastest approach would be find the 4-byte
boundary and start reading and comparing 4 bytes at a time. When a mismatch is found, you''ll dig in and compare them at byte/word level (depending on if your encoding is 8-bit or 16-bit)

In x86 asm, you should use the string optimized lodsb, cmpsb instructions.

-vJ

"Beeeeeves" <1234512345789123456789> wrote in message
news:uy******************@TK2MSFTNGP10.phx.gbl...

有没有快速的方法在两个字符串中找到不同
的第一个字符的索引？

例如，如果我有字符串
" abcdefghijkl"
和
abcdefxyz
我希望返回值为6.

在C＃或C ++中。 （我显然知道如何通过循环
字符数组中的字符来做到这一点，但我想知道是否有一些
smart-alec内存操作函数，asm甚至或正则表达式我可以
用它来做。）

Is there a quick way to find the index of the first character different in two strings?

For instance, if I had the strings
"abcdefghijkl"
and
"abcdefxyz"
I would want the return value to be 6.

Either in C# or C++. (I obviously know how to do it by looping through the characters in the character array, but I was wondering if there was some
smart-alec memory-manipulation function, asm even, or regexes I could use that would do it.)

Thanks

这篇关于字符串中的第一个不同字符的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！