#!/usr/bin/perl -w # Copyright 2010, 2011, 2012 Kevin Ryde # This file is part of Math-PlanePath. # # Math-PlanePath is free software; you can redistribute it and/or modify it # under the terms of the GNU General Public License as published by the Free # Software Foundation; either version 3, or (at your option) any later # version. # # Math-PlanePath is distributed in the hope that it will be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License # for more details. # # You should have received a copy of the GNU General Public License along # with Math-PlanePath. If not, see <http://www.gnu.org/licenses/>. # Usage: perl square-numbers.pl # # Print the SquareSpiral numbers in a grid like # # 37 36 35 34 33 32 31 # 38 17 16 15 14 13 30 # 39 18 5 4 3 12 29 # 40 19 6 1 2 11 28 # 41 20 7 8 9 10 27 # 42 21 22 23 24 25 26 # 43 44 45 46 47 ... # # See numbers.pl for a more sophisticated program. use 5.004; use strict; use List::Util 'min', 'max'; use Math::PlanePath::SquareSpiral; my $n_max = 115; my $path = Math::PlanePath::SquareSpiral->new; my %rows; my $x_min = 0; my $x_max = 0; my $y_min = 0; my $y_max = 0; foreach my $n ($path->n_start .. $n_max) { my ($x, $y) = $path->n_to_xy ($n); $rows{$x}{$y} = $n; $x_min = min($x_min, $x); $x_max = max($x_max, $x); $y_min = min($y_min, $y); $y_max = max($y_max, $y); } my $cellwidth = length($n_max) + 2; foreach my $y (reverse $y_min .. $y_max) { foreach my $x ($x_min .. $x_max) { printf ('%*s', $cellwidth, $rows{$x}{$y} || ''); } print "\n"; } exit 0;