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#!/usr/bin/perl
#
# Challenge 2: "Write a script to implement Priority Queue. It is like
# regular queue except each element has a priority associated with it. In a
# priority queue, an element with high priority is served before an element
# with low priority. It should serve the following operations:
#
# 1) is_empty: check whether the queue has no elements.
#
# 2) insert_with_priority: add an element to the queue with an associated
# priority.
#
# 3) pull_highest_priority_element: remove the element from the queue that
# has the highest priority, and return it. If two elements have the same
# priority, then return element added first.
#
# "
#
# My notes: At last, a nicely specified problem to implement a nice data
# type. meat and drink to me! I've split out the Priority Queue
# implementation into the module PQ.pm, minimally-OO in order to
# get free magic PQ printing via interpolation and the magic of
# stringification.
use strict;
use warnings;
use Function::Parameters;
use Data::Dumper;
use lib qw(.); # I hate this!
use PQ;
my $pq = PQ->new();
foreach my $arg (@ARGV)
{
if( $arg =~ /^(\d+):(.+)$/ )
{
$pq->enqueue( $1, $2 );
}
print "pq: $pq\n";
}
while( ! $pq->isempty() )
{
my( $item, $priority ) = $pq->dequeue();
print "item $item, priority $priority\n";
print "pq: $pq\n";
}
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