# Copyright (C) 2008 Toby Thain, toby@telegraphics.com.au

# This program 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 2 of the License, or
# (at your option) any later version.

# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

# Print the solution to VIER NEUN puzzle.
# See: http://groups.google.com/group/comp.lang.tcl/msg/8846d9f7491ba0ba

procedure main()
	sq := []
	every put(sq, string( (32 to 99)^2 ))  # build list of 4-digit squares

	c := table(0)
	res := []
	every v := !sq & n := !sq do  # generate all pairings (Cartesian product)
		if v[3]=n[2] & n[1]=n[4] & *cset(v||n)=6 then {  # test against pattern
			every c[v|n] +:= 1    # count occurrences of left and right squares
			put(res, [v,n])       # store this solution
		}
	every r := !res do
		if 1 = c[r[1]] = c[r[2]] then  # print only solutions where
			write(r[1], " ", r[2])     # each half appears only once
end