NAME
RangeQuery - retrieves the minimum/maximum value from a set within a given range.
SYNOPSIS
use RangeQuery qw(min_value max_value);
my @set = (4,2,8,6,1,2);
my $range = RangeQuery->new(@set);
my $min = $range->min_value(1,3); # 2
my $max = $range->max_value (4, 6); # 6
DESCRIPTION
Retrieves the minimum/maximum value from a set within a given range. The range is represented with two 1-based indexes. It takes O(n log n) to build the object and O(1) to retrieve a value.
METHODS
new
Creates a new RangeQuery object. This builds the appropriate data structure in order to retrieve values efficiently.
max_value
Retrieves the maximum value within a given range. This receives two 1-based indexes.
min_value
Retrieves the minimum value within a given range. This receives two 1-based indexes.
ToDo
Implement the same funcionality with segment trees.
SEE ALSO
You can check a tutorial from TopCoder, http://www.topcoder.com/tc?module=Static&d1=tutorials&d2=lowestCommonAncestor
You can check an implementation in C here http://web.ist.utl.pt/joao.carreira/rmq.html
AUTHOR
João Carreira, joao.carreira@ist.utl.pt
COPYRIGHT AND LICENSE
Copyright (C) 2009 by João Carreira
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.10.0 or, at your option, any later version of Perl 5 you may have available.