#!/usr/bin/perl
use strict;
use YAML qw();

my $kGenLines = 3;
my $history   = eval {YAML::LoadFile('history.yaml')} || {};

# Adjust history
$history->{$_} && --$history->{$_} for keys %$history;

#generate lines
my @alphas = 'A' .. 'M';
my @nums   = 1 .. 5;

LINES: for (1 .. $kGenLines) {
    my @aPool = @alphas;
    my $pair;

    while (@aPool) {
        my @nPool = @nums;
        my $tryAlpha = splice @aPool, rand(@aPool), 1;

        while (@nPool) {
            my $tryNum = splice @nPool, rand(@nPool), 1;

            next if $history->{"$tryAlpha|$tryNum"};

            @alphas = grep {$_ ne $tryAlpha} @alphas;
            @nPool = grep {$_ != $tryNum} @nPool;
            print "$tryAlpha $tryNum\n";
            $history->{"$tryAlpha|$tryNum"} = 5;

            next LINES;
        }
        
        @alphas = grep {$_ ne $tryAlpha} @alphas;
    }
}

YAML::DumpFile('history.yaml', $history);