in reply to LCS algorithm

porl:

The first thing I notice is that you're first initializing your @C array to 0, then you're initializing the first row and column to 0. Since they're already zero, you don't need that. So I'd remove those two loops.

Next, it looks like you're having trouble splitting up your strings. You can do it like so:

my @list_of_characters = split //, 'a string';

You're also using C-style loops, like so:

for(my $i = 0; $i<=$mLength; $i++) { ... }

You may find it easier to read if you'd switch over to a more perlish style, more like:

for my $i (0 .. $mLength) { ... }

You're also using '&' in a function call, which is something you ought to avoid except in certain cases. For general function calls, leave out the '&'.

You've got some off-by-one errors in wikiBacktrack: if $mLength holds the length of a array @m, then $m[$mLength] doesn't exist. If you want to check the value of the last item in the list, perl has a shorthand: -1 refers to the last item, so you can use that instead. (It also offers the $#m variable, which is the index of the last item if you need that value).

There are a few other items, but these should get you going.

Update: Added code tags so an array reference isn't treated as a link.

...roboticus

When your only tool is a hammer, all problems look like your thumb.

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Re^2: LCS algorithm
by porl (Initiate) on Apr 16, 2015 at 11:36 UTC
    Thank-you so much for the direction! I am going to get right on it.