NOTE: use Perl; is on undef hiatus. You can read content, but you can't post it. More info will be forthcoming forthcomingly.

## All the Perl that's Practical to Extract and Report

#### bacek (8813)

bacek
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### Journal of bacek (8813)

Wednesday December 24, 2008
02:31 AM

### Scripting Games, part 3

Next one: find winner of skater contest.

# Calculate score for single result
sub calculate_score(@scores) {
# Sort scores
my @sorted = sort @scores;
# Drop highest and lowest
shift @sorted;
pop @sorted;
# Calculate final score
([+] @sorted)/ +@sorted;
};

# Parse line in form "Ken Myer,55,66,76,67,59,70,54", and return (score, name)
sub parse_line(\$line) {
my @parts = \$line.split(',');
reverse(shift @parts, calculate_score(@parts));
};

# Main cycle. Read file, parse lines, build mapping score=>name
my \$fh = open('skaters.txt') or die;
my %results = map &parse_line, =\$fh;

# Get 3 top results
my @top = %results.keys.sort.reverse[0..2];
# And show them
say %results{\$_}, ': ', \$_ for @top;

I don't know what to say. Solution is straight forward.

02:01 AM

### Scripting Games, part 2

Beginner's events are way too easy. Let's take a look at "advanced".

http://www.microsoft.com/technet/scriptcenter/funzone/games/games08/aevent1.mspx

# First thing first: build letters-to-digits map
my \$pos = 2;
my %l2d;
map { %l2d{\$^a} = \$pos; %l2d{\$^b} = \$pos; %l2d{\$^c} = \$pos++ }, 'a'..'p', 'r'..'y';

# Calculate number representation of word
# join digit for given letters
[~] map { %l2d{ lc \$^a } }, \$word.split('');
};

# Read wordlist and returns hash (number => word).
# Also skips all non-7 chars words
my \$fh = open(\$filename) or die;
map { read_word(\$^a) => \$^a }, grep { \$^a.chars == 7 }, =\$fh;
};

# And say word corresponded to number.
for =\$*IN {
say uc %words{\$_};
}

Funny note: there is no 'scripts' in wordlist.txt :)

01:11 AM

### First post.

Hi.

In response to Pm's "Scripting games in Perl6" I've decided to implement some of them in Perl6.

Task is to calculate number of different pairs of cards.

sub fact(\$n) {
\$n <= 1 ?? 1 !! \$n*fact(\$n-1);
}

sub calculate_pairs(@pairs) {
my %h;
# Calculate number of distinct cards.
++%h{\$_} for @pairs;
# Sum of C^N_2
[+] map { int(fact(\$^a) / 2) }, %h.values;
};

Trivial mathematical solution: number of different pairs for given amount of cards is C^n_2. So, I group cards, calculate number of combinations in different group and sum them.

Little trick: if number of cards in group equals to 1 than int(...) will return 0.

Update: masak++ for pointing to use.perl.org strange reaction on <=