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— 8K bytes
— 1992-10-07
This program and it's associated files are (C) Copyright 1991 by Martin
Gitelson. It is to be distributed as shareware. No commercial use may be
made other than a reasonable fee for reproduction. Please feel free to
distribute by any means, but please keep all the files together. Use at your
own risk. I take no responsibility for any damages that may be caused by
the use of this program.
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OVERVIEW
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The Electronic Cube is an animated Rubik's Cube simulator, solver and
tutorial, for anyone interested in learning the workings of the Rubik's
cube. It contains two solving algorithms; the one that I and most people
use for solving; plus another using more processes than most people can
possibly remember just to see how few moves it will take to solve any cube.
It doen't start out as a Rubik's Cube program. It started out just
playing around with the drawing commands on my new computer. It started
out drawing circles and elipses and squares and then cubes and then
something that looked like a Rubik's cube and eventually ended up as what
you see here.
This program is the result of almost two years work. It didn't take
nearly that long to write, but it took that long to find, catalog and apply
over 400 processes for the solving algorithm. It also took some time to
learn the c128 and the Amiga. Most of the processes were discovered with
the help of my c128 computer which is still running a search for new and
better processes.
It can check about 6,000,000 per day. That means it can check all the
six move processes in less than a day. The seven move processes take about
2 days. the eight move processes take about 31 days. For nine moves, 480
days. Ten moves would take almost 20 years; and eleven moves 310 years.
Then I have to wade through the data to see what can be used. It is now
finding about 1 or 2 usable processes per week.
Currently, it will solve any cube in under 56 moves with an average of
50 or 51. I am shooting for an average in the high 40's. I think the
maximum should be about 50 to 52 or lower when I find enough good strings.
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HOW TO USE THE PROGRAM
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KEYBOARD:
Typing "u","f","b","r","l","d" will cause any of the six sides; up,
front, back, right, left, down to turn in a clockwise direction.
Prefixing with an "a" will cause an anticlockwise turn. Prefixing
with a "2" causes a half turn.
To orient the cube type "ol","or","ou","od","oc","oa" to orient the
cube left, right, up, down, clockwise, or anticlockwise.
Pressing w before starting to solve causes the solve algorithm to
wait after each piece is placed for a key to be pressed.
Pressing 1 before starting to solve causes the solve algorithm to
wait after each move allowing you to follow along with your cube.
All other keypresses are ignored by the program, except for menu
shortcuts.
MENU
Palette:
Enables you to change colors to suit your preferences.
Enables you to paint each separate piece to match any
scrambled cube you wish to solve. Select one of the six
colors by clicking on it; then move the pointer to the
cube and click again. The color will appear in that
area.
In order for the program to work correctly, the cube must
be painted to match a real world cube. It must have the
correct number of red, blue, yellow etc. squares in a
pattern that a regular real cube would have.
Delay sets the speed of the animation.
Mouse Select:
Enables turning and orienting the cube with the use of
the mouse. Click on the arrow for the direction you want
the cube to move.
Colors are keyed to the color of the center spot on each
surface. When the cube is oriented, the colors change.
If you leave this window open, it greatly slows down the
Best of 24 solve.
Clear Screen:
Clears the bottom portion of the screen.
Solve:
Restores the cube who's picture appears on the screen to
it's store-bought condition before you got it all
confused using a method I learned from a book many years
ago. It takes each piece in turn, conducts a search to
find out where that piece happens to be, then selects one
of the strings to put that piece back in place.
First the upper edges.
Second the upper corners.
Third the four middle layer pieces.
Fourth it places the last corners.
Fifth it twists the last corners.
Sixth it places the last 4 edges.
Seventh it twists the last 4 edges.
This solution takes about 60 to 110 moves.
Fast Solve:
It solves the upper layer one piece at a time. It
selects the cheapest first. The original program
solved them in order. Selecting the cheapest first
saved about 3-4 moves.
Next it solves the middle layer, two at a time.
It attempts to combine steps 4-7 at one time if the
string is available. (There are 15,552 possible
configurations of the last layer alone.)
If the string is not available it combines steps 4 and 5
and sometimes 7, if that string is available. If not it
solves steps 4, 5 and 6 leaving 7 for later.
This method takes between 35 and 80 moves. 80 only when
one of the strings is missing. Only 37 out of 456 are
currently missing.
Best of 24:
Best of 24 is the same as Fast Solve except it solves the
cube, records the number of moves, then orients and
solves it again using the same method. There are 24 ways
to hold a cube. Starting from a different point can
dramatically reduce the number of turns required.
Best of 48:
There is a fourth method. I wrote a function which
chooses the cheapest string for the first pair of pieces
in the middle layer. Most of the time it does the same or
better than Best of 24 but sometimes it is worse. You can
see this method by pushing key #6 with or without the Amiga
key. It just seems to take too long to wait while it
solves 48 times and then selects the best on an A500;
about 40 seconds.
You can also see worst of 24 by pressing the 5 key. This
was to help find errors.
Print:
The P key will print the configuration of the upper
layer. It's only useful if the lower two layers are
intact.
Recall:
Each time at the beginning of the solve, the
configuration of the cube is saved in an array. Recall
will get this position back. After Best of 24, Recall
brings back the best starting position.
Info:
Please send donations. After two years of twisting that
cube, I'm starting to get sick of it. If you like the
program, and would like to see me continue to improve it,
for a donation of $15.00 I will send any future revisions
within the next year to those interested. I'll also send
the source in C. I would also like to hear any
constructive criticisms or bug reports anyone might have.
If these figures sound too high, send what you think it
may be worth.
I also have a version that runs on the c64 if anyone
happens to be interested. It has everything but the Best
of 24 and Recall. This program is actually a port of the
c64 version. Also, if anyone is interested in conducting
their own search for new processes, I'll send you my
search programs which only run on the c128. If enough of
us search, maybe we can chop some time off the 4495 year
estimate for searching 12 moves. Any or all of the above
will be sent for the same donation. I'm not trying to
charge by the program; but remember, it takes time to
make copies.
My address is:
Martin Gitelson
511 W. Evergreen Blvd.
Vancouver, Wa., 98660
USA