Re: Making a dynamic high scores table

[kcott]

G'day chickenlips,

Here's a solution using Tie::File which allows you to keep track of high scores within and between instances of your program running.

#!/usr/bin/env perl

use strict;
use warnings;

use Tie::File;

use constant MAX_HIGH_SCORES_TO_SHOW => 10;

my $high_score_data_file = './pm_high_score.dat';

tie my @high_scores, 'Tie::File', $high_score_data_file or die $!;

while (1) {
    print 'Initials (or Return to end): ';
    chomp (my $initials = <>);
    last unless length $initials;
    my $random_score = 1 + int rand 100;
    print "Random score: $random_score\n";

    print "<<<<<<< Before Adding:\n";
    display_high_scores(\@high_scores, MAX_HIGH_SCORES_TO_SHOW);

    add_high_score(\@high_scores, $random_score, $initials);
    print ">>>>>>> After Adding:\n";
    display_high_scores(\@high_scores, MAX_HIGH_SCORES_TO_SHOW);
}   

untie @high_scores;


sub add_high_score {
    my ($high_scores_ref, $score, $name) = @_;

    my $record = @$high_scores_ref;

    for (0 .. $#$high_scores_ref) {
        if ((split /\s+/, $high_scores_ref->[$_])[0] < $score) {
            $record = $_;
            last;
        }
    }

    splice @$high_scores_ref, $record, 0, join ' ' => $score, $name;

    return;
}

sub display_high_scores {
    my ($high_scores_ref, $max_to_show) = @_;

    $max_to_show = MAX_HIGH_SCORES_TO_SHOW unless defined $max_to_show
+;
    $max_to_show = @$high_scores_ref if $max_to_show > @$high_scores_r
+ef;

    my $printf_pattern = "%-5d  %s\n";

    print "High Score Table\n";

    for (0 .. $max_to_show - 1) {
        printf $printf_pattern => split /\s+/, $high_scores_ref->[$_],
+ 2;
    }

    return;
}

Here's a sample run:

$ cat pm_high_score.dat
cat: pm_high_score.dat: No such file or directory

$ pm_high_score.pl
Initials (or Return to end): AA
Random score: 82
<<<<<<< Before Adding:
High Score Table
>>>>>>> After Adding:
High Score Table
82     AA
Initials (or Return to end): BB
Random score: 69
<<<<<<< Before Adding:
High Score Table
82     AA
>>>>>>> After Adding:
High Score Table
82     AA
69     BB
Initials (or Return to end): 

$ cat pm_high_score.dat
82 AA
69 BB

... ran several times to exceed MAX_HIGH_SCORES_TO_SHOW ...

High Score Table
90     II
90     LL
85     DD
82     AA
81     EE
69     BB
56     CC
55     GG
39     JJ
23     FF
Initials (or Return to end): 

$ cat pm_high_score.dat
90 II
90 LL
85 DD
82 AA
81 EE
69 BB
56 CC
55 GG
39 JJ
23 FF
22 KK
18 HH
16 MM