#!/usr/bin/perl
use strict;
use warnings;
my @universe = (1, 10);
my @ranges = ( [ 1, 3 ], [2, 7], [10, 2] );
       
# Normalize the lists
my @nrm_rng = map { ($$_[0] < $$_[1]) ? $_
                    : ( [ $$_[0]-$universe[1], $$_[1] ],
                        [ $$_[0], $$_[1] + $universe[1]-$universe[0] ] ) 
                  } @ranges;
       
# Dump lists
printf("% 2u ",$_) for $universe[0] .. $universe[1];
print "\n";
print  "-- " for $universe[0] .. $universe[1];          
print "\n";
for my $R (@nrm_rng) {
    printf("%2s ", ($_>= $$R[0] and $_<=$$R[1]) ? "XX" : "")
        for $universe[0] .. $universe[1];
    print ": ($$R[0], $$R[1])\n";
}       

my $arMax;     
my @out;
my @working;   
for my $col ($universe[0] .. $universe[1]) {
        $arMax=undef;
        # Add and remove working lists based on column position
        push @working, grep { $col>=$$_[0] } @nrm_rng;
        @nrm_rng = grep { $col < $$_[0] } @nrm_rng;
        @working = grep { $col<=$$_[1] } @working;

        # Compute result for each list
        for (@working) {
                $$_[2] = 3+2*min(abs($col-$$_[0]),abs($col-$$_[1]));
                if (!defined($arMax)
                        or ($$arMax[2]<$$_[2])
                        or ($$arMax[2]==$$_[2] and $$arMax[1]<$$_[1]) ) {
                        $arMax=$_;
                }
        }
        $out[$col] = defined($arMax) ? sprintf("% 2u",$$arMax[2]) : ' 1';

#       print "$col ",
#           "wrk: ", join(", ", map { "(".join(",",@$_).")" } @$_, @working), "\n";

        # Remove lists that will no longer give us values
        @working = grep { $_ eq $arMax or $$arMax[1] < $$_[1] } @working;
}
print "FINAL: ", join(' ', @out), "\n";

sub min {
        my ($l, $r) = (@_);
        return ($l<$r) ? $l : $r;
}

##</code><code>##

roboticus@Work: /Work/Perl/PerlMonks
$ perl 868827_ranges_and_such.pl
 1  2  3  4  5  6  7  8  9 10 
-- -- -- -- -- -- -- -- -- -- 
XX XX XX                      : (1, 3)
   XX XX XX XX XX XX          : (2, 7)
XX XX                         : (0, 2)
                           XX : (10, 11)
 5  5  5  7  7  5  3  1  1  3 : FINAL