Damn, hit send too soon.
I think you split the two strings into arrays.
You create:
$bestMatch:=""
$bestMatch_n_words:=0
Then you loop through the shorter array:
For($i;1;size of array(<shorter array>))
$pos1:=Find in array(<longer array>;<shorter array>{$i})
if($pos1>-1) // this word matches
$thisMatch:=<shorter array>{$i} // a string of matches
$n_words:=1
// now you need to loop through the remaining words in <shorter array>
until you stop matching
$j:=$i+1 // the word in <shorter array> to check next
$k:=$pos1+1 // the word in <longer array> that must match <shorter array>
while (<longer array>{$k} = <shorter array>{$j}) & ( $j< size of
array(<shorter array>))
$thisMatch:=$thisMatch+" "+<shorter array>{$j}
$n_words:=$n_words+1
end while
if($n_words>$bestMatch_n_words)
$bestMatch_n_words:=$n_words
$bestMatch:=$thisMatch
end if
end if
End for
Use Split string if you can use collections and it should be pretty darn
fast. Also need to decide what to do with matches of equal length.
On Thu, Aug 22, 2019 at 9:35 PM Kirk Brooks <[email protected]> wrote:
> Chip,
> I think you split the two strings into arrays.
> You create two more arrays: $aMatches, and $aNumWords (unless by 'length'
> you mean number of characters)
>
> The you look through the shorter array:
>
> For($i;1;size of array(<shorter array>)
>
> $pos1:=Find in array(<longer array>;$<shorter array>{$i})
>
> if($pos1>-1) // this word matches
>
> $thisMatch:=<shorter array>{$i} // a string of matches
>
> $n_words:=1
>
> // now you need to loop through the remaining words in <shorter array>
> until you stop matching
>
> $j:=$i+1 // the word in <shorter array> to check next
>
> $k:=$pos1+1 // the word in <longer array> that must match <shorter array>
>
> while (<longer array>{$k} = <shorter array>{$j}) & ( $j< size of
> array(<shorter array>))
>
> $thisMatch:=$thisMatch+" "+<shorter array>{$j}
>
> $n_words:=$n_words+1
>
> end while
>
>
> end if
>
> End for
>
>
> On Thu, Aug 22, 2019 at 1:13 PM Chip Scheide via 4D_Tech <
> [email protected]> wrote:
>
>> Given 2 strings,
>> I want to find, and return, the longest substring which is the same in
>> both, regardless where in either string the longest substring starts.
>>
>> ex:
>> 1- This is my dog
>> 2- My dog does not have fleas
>> longest common string is 'my dog'
>>
>> how to go about this, efficiently?
>> I am assuming that there is regex black magic that would do this.
>>
>> ---------------
>> Gas is for washing parts
>> Alcohol is for drinkin'
>> Nitromethane is for racing
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>
>
>
> --
> Kirk Brooks
> San Francisco, CA
> =======================
>
> What can be said, can be said clearly,
> and what you can’t say, you should shut up about
>
> *Wittgenstein and the Computer *
>
>
--
Kirk Brooks
San Francisco, CA
=======================
What can be said, can be said clearly,
and what you can’t say, you should shut up about
*Wittgenstein and the Computer *
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