"Special sting comparison"

[greekgoddj]

Greetings,

I am trying to compare strings together in order to extract the common parts in them. For example, if one string is "Twinke twinkle little star" and the second string is "Twinke twinkle little car", I would like to get the similar section of them, which in this case is "Twinke twinkle little". CString.Compare() (which is the same as strcmp()) do not do that obviously. Does anybody know of an existing function somewhere that whould do the above, or at least return the number of characters that are similar?

Thanks,

Aristotel

[wildfrog]

You can start by searching google for "longest common substring".

- petter

[greekgoddj]

Great..thanks...

I was searching for "compare common strings." With "longest common substring", I get lots of results.


Thanks!

[Mike Harnad]

Give this a shot:

CString str("Twinkle twinkle little star");
CString str2("Twinkle twinkle little car");
CString res = str.SpanIncluding(str2);

Note: you may have to strip trailing spaces.

[Igor Vartanov]

I was searching for "compare common strings." With "longest common substring", I get lots of results.

You'd have to try it yourself instead of inet punishing:

#include <windows.h>
#include <atlstr.h>
#include <stdio.h>

CString str("Twinkle twinkle little star");
CString str2("Twinkle twinkle little car");

int main()
{
    LPCTSTR p1 = str, p2 = str2;
    int idx;

	for(idx = 0; *p1 && *p2; idx++)
	{
		if( *p1 != *p2 )
			break;
		++p1;
		++p2;
	}

	CString longestSubstr = str.Left(idx);
	printf("substr: \"%s\"\n", longestSubstr);
}