Re: Runs and Sequences

Here's a kinda fun solution. Can you see how it works?

use warnings;
use strict;

my $flips = 'TTHHHHTHHHHHHTHT';
my $flops = substr $flips, 1;
my ($maxT, $maxH, $side) = (0, 0, substr $flops, 0, 1);
my $toggles = ($flips ^ $flops);

$toggles =~ tr/\0\x1c/01/;
my @runs = $toggles =~ /(0*1)/g;

for my $run (@runs)
  {
  $maxT = length $run if $side eq 'T' && length $run > $maxT;
  $maxH = length $run if $side eq 'H' && length $run > $maxH;
  $side = $side eq 'T' ? 'H' : 'T';
  }

print "Longest heads run is $maxH\n";
print "Longest tails run is $maxT\n";
[download]

Prints:

Longest heads run is 6
Longest tails run is 2
[download]

Perl is Huffman encoded by design.

Comment on Re: Runs and Sequences Select or Download Code

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Re^2: Runs and Sequences by twofish (Initiate) on Sep 09, 2005 at 13:06 UTC
Neat, that works to. Though of course it doesn't actually generate the data, you'd have to save the output of the code i posted to a file.txt and then read that in. I'm not sure if you could cache a spetillion chars... ?	[reply]
Re^3: Runs and Sequences by GrandFather (Saint) on Sep 09, 2005 at 18:36 UTC
Hey, we don't have to give you the whole answer in one hit here :) Exercise for the student: Add the data generation code for some given finite number of tosses Adapt the resulting code to deal with very long series You should reply to this with your solution. For bonus marks you should compare the execution time for this technique with other techniques that have, or may be, posted. Have fun. Perl is Huffman encoded by design.	[reply]