DesignerEric Harshbarger; firstname.lastname@example.org
Dates of DesignJune 2004
Date of first public disclosure or manufactureJune 2004
Materials usedABS plastic
SolutionBelow is one possible solution (found by myself, Eric Harshbarger). It is not the best known. In the notation below, the six blocks are referred to by their unique sizes (largest area they may cover when lying flat): 9, 6, 4, 3, 2, 1. A move is indicated by a "#d" code where "#" is the block moved, and "d" is the direction moved (so, "3R" would indicate rolling the 3-block to the right).
The starting arrangement assumes that the board is oriented such that red squares dominate the left side of the board; uncovered blue and yellow empty spaces of the board (at the start) are shown by "b" and "y" respectively. The square blocks can be oriented in a couple of ways. In the starting position this example solution, it is assumed that the 9 and 1 blocks have blue side-squares along their left/right edges, while the 4 block has its blue side-squares along the top and bottom.
An ASCII representation of the board is below:
999yyyy 999yyyy 99944yy 22144bb 66333bb 66bbbbbHere is a solution in 64 moves:
3D,3D,4R,4D,4L,4U,4R,4D,4D,1R, 1R,1R,1U,1U,2R,2R,2R,6U,6R,3U, 3R,6D,6D,9R,9D,9L,9U,9R,2L,2L, 3L,3L,9D,9R,3R,2R,2R,2D,1D,1D, <-- (blue squares covered at this point -- 9U,1U,1U,1U,3L,6U,6U,6U,6R,4L, "interim goal" achieved after 40 moves), 4U,4U,4U,4U,2L,2U,2L,2U,2U,2R, 3U,3R,3R,3UThe two photographs show Explore puzzle in the initial start arrangement above, and then the board after the first move (3D).
Puzzle ClassificationRolling Block/Maze.
Additional informationThis puzzle was purposely designed to be "open-ended" in the sense that a definitive solution is not known (for that matter, the "best" starting position is not even known). Short of extensive computer analysis or a complex proof, it is not immediately clear what the best (shortest number of moves) solution might be. The user is encouraged to find a solution, and then "explore" with the blocks and try to find a better solution.
The official goal is to start the blocks on the red squares and end up on yellow squares after achieving the blue squares. This could be abbreviated as the "R>B>Y" challenge. Of course, other challenges are possible (for example, "B>R>Y"). It is interesting to note that there is a (very efficient) solution to "R>B" which may not be extended to solving "R>B>Y".
I assembled this puzzle by hand. I have no immediate plans to sell it, but if there is interest in additional copies being made, I will consider it (and, of course, if a manufacturer wishes to approach me about marketing it, I am open to that).
If there are any question about the above instructions, do not hesitate to contact me.
Better SolutionMy friend, Robert Ford, has obtained the best solution to date for the R>B>Y challenge -- 47 moves. Starting arrangement:
999yyyy 999yyyy 99922yy 33344bb 66144bb 66bbbbb 66bbbbb(9 and 1 block have blue side-squares on left/right sides, the 4 block has blue side-squares on top/bottom).
4R,4D,4L,4L,1R,1D,1D,3R,3R,3D, 3D,3D,2D,2D,2D,9D,9R,9U,9R,9D, 6U,6R,6U,6R,6D,9U,6U,2U,2U,2U, 2U,2U,2R,4U,4U,4R,4U,1U,1U,1U, 1U,1R,1U,3U,3L,3U,3UCopyright 2004, Eric Harshbarger