#!/usr/bin/perl

# http://perlmonks.org/?node_id=1170733

use strict;
use warnings;

my $sea = ((' ' x 10) . "\n") x 10;

sub transpose
  {
  local $_ = $sea;
  tr/<>^v/^v<>/;
  $sea = '';
  $sea .= "\n" while s/^(.)/ $sea .= $1; '' /gem;
  }

for my $ship ( 4,3,3,2,2,2,1,1,1,1 )
  {
  my @places;
  push @places, $-[0] while $sea =~ /(?= {$ship})/g;
  substr $sea, $places[rand @places], $ship,
    ('O', '<>', '<#>', '<##>' )[$ship - 1];
  for (0, 9, 11, 0, 9, 11)
    {
    $sea =~ s/(?<=[<>^v#O].{$_}) | (?=.{$_}[<>^v#O])/~/gs;
    transpose;
    }
  rand > 0.5 and transpose;
  }
tr/ /~/ for $sea;

print $sea;
my @chars = $sea =~ /./g;

use Tk; # for http://perlmonks.org/?node_id=1170638

my $mw = MainWindow->new( -title => "Battleship" );
for my $y (0..9)
  {
  for my $x (0..9)
    {
    my ($char, $b) = shift @chars;
    $b = $mw->Button( -font => 'courier 24', -text => ' ',
      -command => sub {$b->configure(-text => $char) },
      )->grid(-row => $y, -column => $x);
    }
  }

MainLoop;