#!/usr/local/bin/perl 
# $Id: matrix.perl,v 1.1 2000/12/29 06:10:10 doug Exp $
# http://www.bagley.org/~doug/shootout/

# This program based on the original from:
# "The What, Why, Who, and Where of Python" By Aaron R. Watters
# http://www.networkcomputing.com/unixworld/tutorial/005/005.html

# modified to pass rows and cols, and avoid matrix size checks
# I've sped up the original quite a bit by removing some loop
# invariants and declaring "use integer"

use strict;
use integer;

my $size = 30;

sub mkmatrix {
    my($rows, $cols) = @_;
    --$rows; --$cols;
    my $count = 1;
    my @mx = ();
    foreach (0 .. $rows) {
    my @row = ();
    $row[$_] = $count++ foreach (0 .. $cols);
    push(@mx, \@row);
    }
    return(\@mx);
}

# mmult contributed by Tony Bowden

sub mmult {
    my ($rows, $cols, $m1, $m2) = @_;
    my $m3 = [];
    --$rows; --$cols;
    for my $i (0 .. $rows) {
        for my $j (0 .. $cols) {
            $m3->[$i][$j] += $m1->[$i][$_] * $m2->[$_][$j] for 0..$cols;
        }
    }
    return $m3;
}

#sub mmult {
#    my ($rows, $cols, $m1, $m2) = @_;
#    my @m3 = ();
#    --$rows; --$cols;
#    for my $i (0 .. $rows) {
#    my @row = ();
#    my $m1i = $m1->[$i];
#    for my $j (0 .. $cols) {
#        my $val = 0;
#        for my $k (0 .. $cols) {
#        $val += $m1i->[$k] * $m2->[$k]->[$j];
#        }
#        push(@row, $val);
#    }
#    push(@m3, \@row);
#    }
#    return(\@m3);
#}

my $N = $ARGV[0] || 1;

my $m1 = mkmatrix($size, $size);
my $m2 = mkmatrix($size, $size);
my $mm;
while ($N--) {
    $mm = mmult($size, $size, $m1, $m2);
}
print "$mm->[0]->[0] $mm->[2]->[3] $mm->[3]->[2] $mm->[4]->[4]\n";