==> competition/games/cube.s <== Johan Myrberger's list of 3x3x3 cube puzzles (version 930222) Comments, corrections and contributions are welcome! MAIL: myrberger@e.kth.se Snailmail: Johan Myrberger Hokens gata 8 B S-116 46 STOCKHOLM SWEDEN A: Block puzzles A.1 The Soma Cube ______ ______ ______ ______ |\ \ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | \_____\ | | |____ _____| | | | | |____ | | |____ |\| | \ |\ \| | |\| | \ |\| | \ | *_____|_____\ | \_____*_____| | *_____|_____\ | *_____|_____\ | |\ \ | | |\ \ | | | |\ \ | | | | \| \_____\ | \| \_____\ | \| | \_____\ \| | | * | |___| * | |___| *_____| | | *_____|_____| \| | \| | \| | *_____| *_____| *_____| ______ ______ ____________ |\ \ |\ \ |\ \ \ | \_____\ | \_____\ | \_____\_____\ | | |__________ _____| | |____ _____| | | | |\| | \ \ |\ \| | \ |\ \| | | | *_____|_____\_____\ | \_____*_____|_____\ | \_____*_____|_____| | | | | | | | | | | | | | | \| | | | \| | | | \| | | *_____|_____|_____| *_____|_____|_____| *_____|_____| A.2 Half Hour Puzzle ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | | |__________ _____| | |____ | | |__________ |\| | \ \ |\ \| | \ |\| | \ \ | *_____|_____\_____\ | \_____*_____|_____\ | *_____|_____\_____\ | | | | | | | | | | | | |\ \ | \| | | | \| | | | \| | \_____\ | *_____|_____|_____| *_____|_____|_____| *_____| | |___| \| | *_____| ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ _____| | | _____| | | | | | |\ \| | |\ \| | |\| | | \_____*_____| | \_____*_____|______ ___|_*_____|______ | |\ \ | | | |\ \ \ |\ \ \ \ \| \_____\ | \| | \_____\_____\ | \_____\_____\_____\ * | |___| *_____| | | | | | | | | \| | \| | | \| | | | *_____| *_____|_____| *_____|_____|_____| A.3 Steinhaus's dissected cube ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | | |__________ _____| | | | | |____ |\| | \ \ |\ \| | |\| | \ | *_____|_____\_____\ | \_____*_____| | *_____|_____\ | | | | | | |\ \ | | | |\ \ \| | | | \| \_____\ | \| | \_____\ *_____|_____|_____| * | |___| *_____| | | \| | \| | *_____| *_____| ____________ ______ ______ |\ \ \ |\ \ |\ \ | \_____\_____\ | \_____\ | \_____\ | | | | | | | ___________| | | \| | | |\| | |\ \ \| | *_____|_____|______ _________|_*_____| | \_____\_____*_____| \ |\ \ \ |\ \ \ \ | | |\ \ | \| \_____\_____\ | \_____\_____\_____\ \| | \_____\ | * | | | | | | | | *_____| | |___| \| | | \| | | | \| | *_____|_____| *_____|_____|_____| *_____| A.4 ______ |\ \ | \_____\ | | |____ Nine of these make a 3x3x3 cube. |\| | \ | *_____|_____\ | | | | \| | | *_____|_____| A.5 ______ ____________ |\ \ |\ \ \ | \_____\ | \_____\_____\ ____________ | | |____ | | | | |\ \ \ |\| | \ |\| | | | \_____\_____\ | *_____|_____\ | *_____|_____| | | | | | | | | | | | | \| | | \| | | \| | | *_____|_____| *_____|_____| *_____|_____| ______ ______ |\ \ |\ \ | \_____\ | \_____\ ______ ______ | | |____ | | |__________ |\ \ |\ \ |\| | \ |\| | \ \ | \_____\ | \_____\ | *_____|_____\ | *_____|_____\_____\ | | |___| | | | | | |____ | | | | | |\| | \| | |\| | | \ |\| | | | | *_____|_____*_____| | *_____|_____|_____\ | *_____|_____|_____| | | | | | | | | | | | | | | | \| | | | \| | | | \| | | | *_____|_____|_____| *_____|_____|_____| *_____|_____|_____| A.6 ______ ______ ______ ______ |\ \ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | \_____\ | | |____ _____| | | | | |____ | | |____ |\| | \ |\ \| | |\| | \ |\| | \ | *_____|_____\ | \_____*_____| | *_____|_____\ | *_____|_____\ | |\ \ | | |\ \ | | | |\ \ | | | | \| \_____\ | \| \_____\ | \| | \_____\ \| | | * | |___| * | |___| *_____| | | *_____|_____| \| | \| | \| | *_____| *_____| *_____| ______ ____________ ____________ |\ \ |\ \ \ |\ \ \ | \_____\ | \_____\_____\ | \_____\_____\ _____| | |____ _____| | | | _____| | | | |\ \| | \ |\ \| | | |\ \| | | | \_____*_____|_____\ | \_____*_____|_____| | \_____*_____|_____| | | | | | | | | | | | | | \| | | | \| | | \| | | *_____|_____|_____| *_____|_____| *_____|_____| A.7 ____________ |\ \ \ | \_____\_____\ | | | | |\| | | Six of these and three unit cubes make a 3x3x3 cube. | *_____|_____| | | | | \| | | *_____|_____| A.8 Oskar's ____________ ______ |\ \ \ |\ \ | \_____\_____\ | \_____\ _____| | | | | | |__________ __________________ |\ \| | | |\| | \ \ |\ \ \ \ | \_____*_____|_____| x 5 | *_____|_____\_____\ | *_____\_____\_____\ | | | | | | | | | | | | | | \| | | \| | | | \| | | | *_____|_____| *_____|_____|_____| *_____|_____|_____| A.9 Trikub ____________ ______ ______ |\ \ \ |\ \ |\ \ | \_____\_____\ | \_____\ | \_____\ | | | | | | |__________ _____| | |____ |\| | | |\| | \ \ |\ \| | \ | *_____|_____| | *_____|_____\_____\ | \_____*_____|_____\ | | | | | | | | | | | | | | \| | | \| | | | \| | | | *_____|_____| *_____|_____|_____| *_____|_____|_____| ______ ______ ____________ |\ \ |\ \ |\ \ \ | \_____\ | \_____\ | \_____\_____\ | | |____ | | |____ _____| | | | |\| | \ |\| | \ |\ \| | | | *_____|_____\ | *_____|_____\ | \_____*_____|_____| | |\ \ | | | |\ \ | | | | \| \_____\ | \| | \_____\ \| | | * | |___| *_____| | | *_____|_____| \| | \| | *_____| *_____| and three single cubes in a different colour. The object is to build 3x3x3 cubes with the three single cubes in various positions. E.g: * * * as center * * * as edge * *(3) as * *(2) as * S * * * * *(2)* space *(2)* center * * * * * S (1)* * diagonal (2)* * diagonal (The other two variations with the single cubes in a row are impossible) A.10 ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ _____| | | | | |____ | | |____ |\ \| | |\| | \ |\| | \ | \_____*_____| | *_____|_____\ ___|_*_____|_____\ | |\ \ | | | |\ \ |\ \ \ | \| \_____\ | \| | \_____\ | \_____\_____\ | * | |___| *_____| | | | | | |___| \| | \| | \| | | *_____| *_____| *_____|_____| ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | | |__________ _____| | |____ | | |____ |\| | \ \ |\ \| | \ |\| | \ | *_____|_____\_____\ | \_____*_____|_____\ | *_____|_____\______ | |\ \ | | | | | | | | | |\ \ \ \| \_____\ | | \| | | | \| | \_____\_____\ * | |___|_____| *_____|_____|_____| *_____| | | | \| | \| | | *_____| *_____|_____| B: Coloured blocks puzzles B.1 Kolor Kraze Thirteen pieces. Each subcube is coloured with one of nine colours as shown below. The object is to form a cube with nine colours on each face. ______ |\ \ | \_____\ | | | ______ ______ ______ ______ ______ ______ |\| 1 | |\ \ |\ \ |\ \ |\ \ |\ \ |\ \ | *_____| | \_____\ | \_____\ | \_____\ | \_____\ | \_____\ | \_____\ | | | | | | | | | | | | | | | | | | | | | |\| 2 | |\| 2 | |\| 2 | |\| 4 | |\| 4 | |\| 7 | |\| 9 | | *_____| | *_____| | *_____| | *_____| | *_____| | *_____| | *_____| | | | | | | | | | | | | | | | | | | | | | \| 3 | \| 3 | \| 1 | \| 1 | \| 5 | \| 5 | \| 5 | *_____| *_____| *_____| *_____| *_____| *_____| *_____| ______ ______ ______ ______ ______ ______ |\ \ |\ \ |\ \ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | \_____\ | \_____\ | \_____\ | | | | | | | | | | | | | | | | | | |\| 9 | |\| 9 | |\| 3 | |\| 6 | |\| 6 | |\| 6 | | *_____| | *_____| | *_____| | *_____| | *_____| | *_____| | | | | | | | | | | | | | | | | | | \| 7 | \| 8 | \| 8 | \| 8 | \| 7 | \| 4 | *_____| *_____| *_____| *_____| *_____| *_____| B.2 Given nine red, nine blue and nine yellow cubes. Form a 3x3x3 cube in which all three colours appears in each of the 27 orthogonal rows. B.3 Given nine red, nine blue and nine yellow cubes. Form a 3x3x3 cube so that every row of three (the 27 orthogonal rows, the 18 diagonal rows on the nine square cross-sections and the 4 space diagonals) contains neither three cubes of like colour nor three of three different colours. B.4 Nine pieces, three of each type. Each subcube is coloured with one of three colours as shown below. The object is to build a 3x3x3 cube in which all three colours appears in each of the 27 orthogonal rows. (As in B.2) ______ ______ ______ |\ \ |\ \ |\ \ | \_____\ | \_____\ | \_____\ | | |____ | | |____ | | |____ |\| A | \ x 3 |\| B | \ x 3 |\| A | \ x 3 | *_____|_____\ | *_____|_____\ | *_____|_____\ | | | | | | | | | | | | \| B | C | \| A | C | \| C | B | *_____|_____| *_____|_____| *_____|_____| C: Strings of cubes C.1 Pululahua's dice 27 cubes are joined by an elastic thread through the centers of the cubes as shown below. The object is to fold the structure to a 3x3x3 cube. ____________________________________ |\ \ \ \ \ \ \ | \_____\_____\_____\_____\_____\_____\ | | | | | | | | |\| :77|77777|77: | :77|77777|77: | | *__:__|_____|__:__|__:__|_____|__:__| | | : |___| | : | : |___| | : | |\| : | \| 777|777 | \| : | | *__:__|_____*_____|_____|_____*__:__| | | : | | |___| | | : |____ \| 777|77777|77: | \| :77|777 | \ *_____|_____|__:__|_____*__:__|_____|_____\ | | : | | : | | | |\| : | + | 777|77777|77: | | *__:__|__:__|_____|_____|__:__| | | : | : | | | : | \| + | : | :77|77777|777 | *_____|__:__|__:__|_____|_____| | | : | : | \| 777|777 | *_____|_____| C.1.X The C.1 puzzle type exploited by Glenn A. Iba (quoted) INTRODUCTION "Chain Cube" Puzzles consist of 27 unit cubies with a string running sequentially through them. The string always enters and exits a cubie through the center of a face. The typical cubie has one entry and one exit (the ends of the chain only have 1, since the string terminates there). There are two ways for the string to pass through any single cubie: 1. The string enters and exits non-adjacent faces (i.e. passes straight through the cubie) 2. It enters and exits through adjacent faces (i.e. makes a "right angle" turn through the cubie) Thus a chain is defined by its sequence of straight steps and right angle turns. Reversing the sequence (of course) specifies the same chain since the chain can be "read" starting from either end. Before making a turn, it is possible to "pivot" the next cubie to be placed, so there are (in general) 4 choices of how to make a "Turn" in 3-space. The object is to fold the chain into a 3x3x3 cube. It is possible to prove that any solvable sequence must have at least 2 straight steps. [The smallest odd-dimensioned box that can be packed by a chain of all Turns and no Straights is 3x5x7. Not a 3x3x3 puzzle, but an interesting challenge. The 5x5x5 can be done too, but its not the smallest in volume]. With the aid of a computer search program I've produced a catalog of the number of solutions for all (solvable) sequences. Here is an example sequence that has a unique solution (up to reflections and rotations): (2 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1) the notation is a kind of "run length" coding, where the chain takes the given number of steps in a straight line, then make a right-angle turn. Equivalently, replace 1 by Turn, 2 by Straight followed by a Turn. The above sequence was actually a physical puzzle I saw at Roy's house, so I recorded the sequence, and verified (by hand and computer) that the solution is unique. There are always 26 steps in a chain, so the "sum" of the 1's and 2's in a pattern will always be 26. For purposes of taxonomizing, the "level" of a string pattern is taken to be the number of 2's occuring in its specification. COUNTS OF SOLVABLE AND UNIQUELY SOLVABLE STRING PATTERNS (recall that Level refers to the number of 2's in the chain spec) Level Solvable Uniquely Patterns Solvable 0 0 0 1 0 0 2 24 0 3 235 15 4 1037 144 5 2563 589 6 3444 1053 7 2674 1078 8 1159 556 9 303 187 10 46 34 11 2 2 12 0 0 13 0 0 _______ ______ Total Patterns: 11487 3658 SOME SAMPLE UNIQUELY SOLVABLE CHAINS In the following the format is: ( #solutions palindrome? #solutions-by-start-type chain-pattern-as string ) where #solutions is the total number of solutions up to reflections and rotations palindrome? is T or NIL according to whether or not the chain is a palindrome #solutions by-start-type lists the 3 separate counts for the number of solutions starting the chain of in the 3 distinct possible ways. chain-pattern-as-string is simply the chain sequence My intuition is that the lower level chains are harder to solve, because there are fewer straight steps, and staight steps are generally more constraining. Another way to view this, is that there are more choices of pivoting for turns because there are more turns in the chains at lower levels. Here are the uniquely solvable chains for level 3: (note that non-palindrome chains only appear once -- I picked a "canonical" ordering) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; Level 3 ( 3 straight steps) -- 15 uniquely solvable patterns ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; (1 NIL (1 0 0) "21121111112111111111111") (1 NIL (1 0 0) "21121111111111111121111") (1 NIL (1 0 0) "21111112112111111111111") (1 NIL (1 0 0) "21111111211111111111112") (1 NIL (1 0 0) "12121111111111112111111") (1 NIL (1 0 0) "11211211112111111111111") (1 NIL (1 0 0) "11112121111111211111111") (1 NIL (1 0 0) "11112112112111111111111") (1 NIL (1 0 0) "11112112111111211111111") (1 NIL (1 0 0) "11112111121121111111111") (1 NIL (1 0 0) "11112111111211211111111") (1 NIL (1 0 0) "11112111111112121111111") (1 NIL (1 0 0) "11111121122111111111111") (1 NIL (1 0 0) "11111112122111111111111") (1 NIL (1 0 0) "11111111221121111111111") C.2 Magic Interlocking Cube (Glenn A. Iba quoted) This chain problem is marketed as "Magic Interlocking Cube -- the Ultimate Cube Puzzle". It has colored cubies, each cubie having 6 distinctly colored faces (Red, Orange, Yellow, Green, Blue, and White). The object is to fold the chain into a 3x3x3 cube with each face being all one color (like a solved Rubik's cube). The string for the chain is actually a flexible rubber band, and enters a cubie through a (straight) slot that cuts across 3 faces, and exits through another slot that cuts the other 3 faces. Here is a rough attempt to picture a cubie: (the x's mark the slots cut for the rubber band to enter/exit) __________ / /| xxxxxxxxxxx | / / x | /_________/ x | | | x | | | | | | / | x | / | x | / | x |/ -----x----- Laid out flat the cubie faces would look like this: _________ | | | | | x | | x | |____x____|_________ _________ _________ | x | | | | | x | | | | | x | x x x x x x x x x x x | | x | | | | |____x____|_________|_________|_________| | x | | x | | x | | | |_________| The structure of the slots gives 3 choices of entry face, and 3 choices of exit face for each cube. It's complicated to specify the topology and coloring but here goes: Imagine the chain stretched out in a straight line from left to right. Let the rubber band go straight through each cubie, entering and exiting in the "middle" of each slot. It turns out that the cubies are colored so that opposite faces are always colored by the following pairs: Red-Orange Yellow-White Green-Blue So I will specify only the Top, Front, and Left colors of each cubie in the chain. Then I'll specify the slot structure. Color sequences from left to right (colors are R,O,Y,G,B,and W): Top: RRRRRRRRRRRRRRRRRRRRRRRRRRR Front: YYYYYYYYYYYYWWWYYYYYYYYYYYY Left: BBBBBGBBBGGGGGGGGGBBGGGGBBB For the slots, all the full cuts are hidden, so only the "half-slots" appear. Here is the sequence of "half slots" for the Top (Red) faces: (again left to right) Slots: ><><><><<><><<<><><>>>>><>> Where > = slot goes to left < = slot goes to right To be clearer, > (Left): _______ | | | | xxxxx | | | |_______| < (Right): _______ | | | | | xxxxx | | |_______| Knowing one slot of a cubie determines all the other slots. I don't remember whether the solution is unique. In fact I'm not certain whether I actually ever solved it. I think I did, but I don't have a clear recollection. D: Blocks with pins D.1 Holzwurm (Torsten Sillke quoted) Inventer: Dieter Matthes Distribution: Pyramo-Spiele-Puzzle Silvia Heinz Sendbuehl 1 D-8351 Bernried tel: +49-9905-1613 Pieces: 9 tricubes Each piece has one hole (H) which goes through the entire cube. The following puctures show the tricubes from above. The faces where you see a hole are marked with 'H'. If you see a hole at the top then there is a hole at the bottom too. Each peace has a worm (W) one one face. You have to match the holes and the worms. As a worm fills a hole completely, you can not put two worms at both ends of the hole of the same cube. __H__ _____ _____ | | | | | | | | | |W | | |_____|_____ |_____|_____ |_____|_____ | | | | | | | | | | | |W | | |H | H | |W |_____|_____| |_____|_____| |_____|_____| __H__ _____ _____ | | | | | | | | | | | W | |_____|_____ |_____|_____ |_____|_____ | | | | | | | | | | | | | W | H | | | H | |_____|_____| |_____|_____| |_____|_____| W __W__ _____ _____ | | | | | | | | H| |H | | |_____|_____ |_____|_____ |_____|_____ | | | | | | | | | | | H | | | | H| | W | |_____|_____| |_____|_____| |_____|_____| W Aim: build a 3*3*3 cube without a worm looking outside. take note, it is no matching problem, as | | worm> H| |H geometry/coloring/cheese.cube.p <== A cube of cheese is divided into 27 subcubes. A mouse starts at one corner and eats through every subcube. Can it finish in the middle? ==> geometry/coloring/cheese.cube.s <== Give the subcubes a checkerboard-like coloring so that no two adjacent subcubes have the same color. If the corner subcubes are black, the cube will have 14 black subcubes and 13 white ones. The mouse always alternates colors and so must end in a black subcube. But the center subcube is white, so the mouse can't end there. E.4 Cut the 3*3*3 cube into single cubes. At each slice you can rearrange the blocks. Can you do it with fewer than 6 cuts?