#!/usr/bin/perl -w

my %ngramme;
my @korpus;
my @ngramm_temp;
my $n_gramm_laenge = $ARGV[0];
my $minfreq = 3;
my $korpus = 'Pfad\\zum\\Korpus.txt';
my $outputdatei = "ngram_fertig.txt";

open(OUTPUT, "> $outputdatei");
open (DATEI,  "< $korpus");

while (<DATEI>) {
    chomp ($_);
    my @zeile = split /<\/w>/,$_;
    foreach(@zeile) {
        push (@korpus,$_);
    }
    undef (@zeile);
}

foreach (@korpus) {
    if($_ =~ m/lemma=(".*?")>/){
    $lemma = $1;}
    push(@lemmata,$lemma);
}

foreach (@lemmata) {
    push (@ngramm_temp,$_);
    my $array_laenge = @ngramm_temp;
    if ($array_laenge == $n_gramm_laenge) {
        my $ngramm = join (" -> ",@ngramm_temp);
        shift @ngramm_temp;
        if (defined $ngramme{$ngramm}) {
            $ngramme{$ngramm}++;
        }
        else {
            $ngramme{$ngramm} = 1;
        }
    }
}

print OUTPUT "digraph myGraph {\n";

foreach my $key (sort { $ngramme{$a} <=> $ngramme{$b} } keys %ngramme) {
    if ($ngramme{$key} >= $minfreq) {
        print OUTPUT "\t$key [weight=\"$ngramme{$key}\"];\n";
    }
}
print OUTPUT "}";
close(DATEI);
close(OUTPUT);