ch18.023_prob

Perl Best Practices the source code

##############################################################################
## Code fragment (NOT RECOMMENDED) from Chapter 18 of "Perl Best Practices" ##
##     Copyright (c) O'Reilly & Associates, 2005. All Rights Reserved.      ##
##  See: http://www.oreilly.com/pub/a/oreilly/ask_tim/2001/codepolicy.html  ##
##############################################################################


# Standard modules...
use strict;
use warnings;
use IO::Prompt;
use Carp;
use English qw( -no_match_vars );
use Data::Alias;
use Readonly;


sub is_monotonic_increasing {
    my ($data_ref) = @_;
    for my $i (1..$#{$data_ref}) {
        return 0 unless $data_ref->[$i-1] > $data_ref->[$i];
    }
    return 1;
}


carp 'Oops! [1,2,2,3]' if  is_monotonic_increasing( [1,2,2,3] );
carp 'Oops! [1,2,3,4]' if !is_monotonic_increasing( [1,2,3,4] );
carp 'Oops! [3,2,1,0]' if  is_monotonic_increasing( [3,2,1,0] );