NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part2/14170

Internet Message Format | 1996-08-05 | 1.8 KB

Path: mail2news.demon.co.uk!genesis.demon.co.uk
From: Lawrence Kirby <[e-mail]>
Newsgroups: comp.lang.c
Subject: Re: reversing a string
Date: Fri, 12 Apr 96 12:20:53 GMT
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References: <4k6cjl$[e-mail]> <4k6jks$[e-mail]> <[e-mail]> <[e-mail]> <[e-mail]>
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In article <[e-mail]> [e-mail] "Doug Miller" writes:

>Lawrence Kirby <[e-mail]> wrote:
>>In article <[e-mail]> [e-mail] "Doug Miller" writes:
>>
>>>[e-mail] (Peter Seebach) wrote:
>>>>I can't see a way to reverse in place without a temporary of some sort,
>>>>or a loop of some sort, or something which is fundementally equivalent
>>>>to one of those.  There may be one, but I don't know it.
>>>>
>>>>-s
>>>
>>>How about this:
>>>
>>>void swap (char *s) {
>>>    if (strlen(s) > 1) {
>>
>>strlen() is fundamentally based on a loop.
>
>OK, since the objective is to determine if the string is more than 1 character
> long, we can do
>the same by testing the next character.
>Replace
>        if (strlen(s) > 1)
>with
>        if (*(s + 1))
>and the rest of the algorithm is still valid.

OK, you can do that with this particular strlen() but there are several
others in the function that can't be replaced in this way since they are
used to reference characters at the end of the string.

--
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Lawrence Kirby | [e-mail]
Wilts, England | [e-mail]
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