Knights Problem












6












$begingroup$


There are 2 white knights and 2 black knights positioned at a (3 X 3) chess board. Find the minimum number of moves required to replace the blacks with whites and the whites with blacks.



I tried the above in 19 steps and reckon that I'm wrong. Please help !!



Picture is here



I guess the catch here is to position the knights in



0w0

w0b

0b0



or



0b0

w0b

0w0



0 -> empty space | w -> white knight | b -> black knights



What is your take on this? Here is my solution, but it seems that my answer takes longer number of steps.



EDIT



For some of those who still have some doubts regarding the question, the final configuration should be:



BoW
ooo
BoW










share|improve this question











$endgroup$












  • $begingroup$
    Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    Do you have to source of the puzzle by chance?
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    @North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
    $endgroup$
    – jay
    Jan 30 at 12:13












  • $begingroup$
    This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
    $endgroup$
    – Jaap Scherphuis
    Jan 30 at 13:25










  • $begingroup$
    @jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
    $endgroup$
    – North
    Jan 30 at 14:09
















6












$begingroup$


There are 2 white knights and 2 black knights positioned at a (3 X 3) chess board. Find the minimum number of moves required to replace the blacks with whites and the whites with blacks.



I tried the above in 19 steps and reckon that I'm wrong. Please help !!



Picture is here



I guess the catch here is to position the knights in



0w0

w0b

0b0



or



0b0

w0b

0w0



0 -> empty space | w -> white knight | b -> black knights



What is your take on this? Here is my solution, but it seems that my answer takes longer number of steps.



EDIT



For some of those who still have some doubts regarding the question, the final configuration should be:



BoW
ooo
BoW










share|improve this question











$endgroup$












  • $begingroup$
    Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    Do you have to source of the puzzle by chance?
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    @North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
    $endgroup$
    – jay
    Jan 30 at 12:13












  • $begingroup$
    This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
    $endgroup$
    – Jaap Scherphuis
    Jan 30 at 13:25










  • $begingroup$
    @jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
    $endgroup$
    – North
    Jan 30 at 14:09














6












6








6





$begingroup$


There are 2 white knights and 2 black knights positioned at a (3 X 3) chess board. Find the minimum number of moves required to replace the blacks with whites and the whites with blacks.



I tried the above in 19 steps and reckon that I'm wrong. Please help !!



Picture is here



I guess the catch here is to position the knights in



0w0

w0b

0b0



or



0b0

w0b

0w0



0 -> empty space | w -> white knight | b -> black knights



What is your take on this? Here is my solution, but it seems that my answer takes longer number of steps.



EDIT



For some of those who still have some doubts regarding the question, the final configuration should be:



BoW
ooo
BoW










share|improve this question











$endgroup$




There are 2 white knights and 2 black knights positioned at a (3 X 3) chess board. Find the minimum number of moves required to replace the blacks with whites and the whites with blacks.



I tried the above in 19 steps and reckon that I'm wrong. Please help !!



Picture is here



I guess the catch here is to position the knights in



0w0

w0b

0b0



or



0b0

w0b

0w0



0 -> empty space | w -> white knight | b -> black knights



What is your take on this? Here is my solution, but it seems that my answer takes longer number of steps.



EDIT



For some of those who still have some doubts regarding the question, the final configuration should be:



BoW
ooo
BoW







logical-deduction chess






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jan 30 at 12:10







jay

















asked Jan 30 at 2:22









jayjay

1344




1344












  • $begingroup$
    Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    Do you have to source of the puzzle by chance?
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    @North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
    $endgroup$
    – jay
    Jan 30 at 12:13












  • $begingroup$
    This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
    $endgroup$
    – Jaap Scherphuis
    Jan 30 at 13:25










  • $begingroup$
    @jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
    $endgroup$
    – North
    Jan 30 at 14:09


















  • $begingroup$
    Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    Do you have to source of the puzzle by chance?
    $endgroup$
    – North
    Jan 30 at 3:03










  • $begingroup$
    @North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
    $endgroup$
    – jay
    Jan 30 at 12:13












  • $begingroup$
    This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
    $endgroup$
    – Jaap Scherphuis
    Jan 30 at 13:25










  • $begingroup$
    @jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
    $endgroup$
    – North
    Jan 30 at 14:09
















$begingroup$
Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
$endgroup$
– North
Jan 30 at 3:03




$begingroup$
Welcome to Puzzling SE! If you haven't already done so, please take the tour! You'll also get a free badge :). Normally, asking questions like these are slightly frowned upon as in can bring a lot of speculations or a variety of answers. This one might be okay though, so I would need some confirmation.
$endgroup$
– North
Jan 30 at 3:03












$begingroup$
Do you have to source of the puzzle by chance?
$endgroup$
– North
Jan 30 at 3:03




$begingroup$
Do you have to source of the puzzle by chance?
$endgroup$
– North
Jan 30 at 3:03












$begingroup$
@North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
$endgroup$
– jay
Jan 30 at 12:13






$begingroup$
@North Didn't get your first comment. What type of question is this? Is it not suitable to ask at this platform. Sorry, but I don't have any source.
$endgroup$
– jay
Jan 30 at 12:13














$begingroup$
This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
$endgroup$
– Jaap Scherphuis
Jan 30 at 13:25




$begingroup$
This is a classic puzzle, which I think I've seen discussed in a Martin Gardner book/column, and maybe also in one of H.E. Dudeney's books. Variants of this puzzle have been posted here before, e.g. Desegregate the knights with a different goal, and Switch the knights on a 3x4 board, and Swapping knights on a 4x4 board.
$endgroup$
– Jaap Scherphuis
Jan 30 at 13:25












$begingroup$
@jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
$endgroup$
– North
Jan 30 at 14:09




$begingroup$
@jay No, no, this puzzle is fine, I was just concerned it might warrant a lot of different answers. clearly it didn't though :)
$endgroup$
– North
Jan 30 at 14:09










3 Answers
3






active

oldest

votes


















11












$begingroup$

If you numbered the board like this:




enter image description here




Then it is easy to notice that:




The route of each knights is a cycle of:
$dots - 1 - 6 - 7 - 2 - 9 - 4 - 3 - 8 - dots$


(i.e. from $2$ can go to $7$ or $9$ and etc.)




Therefore:




We want to move white from $1&7$ to $9&3$, for black from the $9&3$ to $1&7$.

It is straightforward that the minimum movement we should take is shifting them all $4$ times to right or left.


Hence, $4 times 4 = 16$ moves is the optimal one.







share|improve this answer









$endgroup$













  • $begingroup$
    that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
    $endgroup$
    – Van
    Jan 30 at 3:39



















4












$begingroup$

Although @athin seems to have proven it impossible, I can't find any problem with my solution in




8 moves




Here it is:




enter image description here
1. Na3 Nc3

2. Nc1 Na1

3. Nc2 Nb2

4. Na2 Nb3




Since the path is cyclic, there are working positions reached along the way too, of course.






share|improve this answer









$endgroup$









  • 1




    $begingroup$
    Eh, can the starting positions be different than the one given by OP?
    $endgroup$
    – athin
    Jan 30 at 6:22










  • $begingroup$
    @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
    $endgroup$
    – Bass
    Jan 30 at 6:49










  • $begingroup$
    OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
    $endgroup$
    – Chronocidal
    Jan 30 at 13:23










  • $begingroup$
    @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
    $endgroup$
    – Bass
    Jan 30 at 13:31



















3












$begingroup$

I can get you down to 16 moves. I don't know if I can do any better.



Start off by




moving all four corners onto the black squares, giving


oWo


BoW


oBo




Then, instead of returning to the original square, move




them onto a corner one rotation away from where they started. This gives:



BoB


ooo


WoW




Eight moves total, so far.



Follow the same process for four more moves, and you wind up with:





oWo


WoB


oBo




and then, four more moves (for a total of sixteen):




BoW


ooo


BoW







share|improve this answer









$endgroup$














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    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    11












    $begingroup$

    If you numbered the board like this:




    enter image description here




    Then it is easy to notice that:




    The route of each knights is a cycle of:
    $dots - 1 - 6 - 7 - 2 - 9 - 4 - 3 - 8 - dots$


    (i.e. from $2$ can go to $7$ or $9$ and etc.)




    Therefore:




    We want to move white from $1&7$ to $9&3$, for black from the $9&3$ to $1&7$.

    It is straightforward that the minimum movement we should take is shifting them all $4$ times to right or left.


    Hence, $4 times 4 = 16$ moves is the optimal one.







    share|improve this answer









    $endgroup$













    • $begingroup$
      that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
      $endgroup$
      – Van
      Jan 30 at 3:39
















    11












    $begingroup$

    If you numbered the board like this:




    enter image description here




    Then it is easy to notice that:




    The route of each knights is a cycle of:
    $dots - 1 - 6 - 7 - 2 - 9 - 4 - 3 - 8 - dots$


    (i.e. from $2$ can go to $7$ or $9$ and etc.)




    Therefore:




    We want to move white from $1&7$ to $9&3$, for black from the $9&3$ to $1&7$.

    It is straightforward that the minimum movement we should take is shifting them all $4$ times to right or left.


    Hence, $4 times 4 = 16$ moves is the optimal one.







    share|improve this answer









    $endgroup$













    • $begingroup$
      that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
      $endgroup$
      – Van
      Jan 30 at 3:39














    11












    11








    11





    $begingroup$

    If you numbered the board like this:




    enter image description here




    Then it is easy to notice that:




    The route of each knights is a cycle of:
    $dots - 1 - 6 - 7 - 2 - 9 - 4 - 3 - 8 - dots$


    (i.e. from $2$ can go to $7$ or $9$ and etc.)




    Therefore:




    We want to move white from $1&7$ to $9&3$, for black from the $9&3$ to $1&7$.

    It is straightforward that the minimum movement we should take is shifting them all $4$ times to right or left.


    Hence, $4 times 4 = 16$ moves is the optimal one.







    share|improve this answer









    $endgroup$



    If you numbered the board like this:




    enter image description here




    Then it is easy to notice that:




    The route of each knights is a cycle of:
    $dots - 1 - 6 - 7 - 2 - 9 - 4 - 3 - 8 - dots$


    (i.e. from $2$ can go to $7$ or $9$ and etc.)




    Therefore:




    We want to move white from $1&7$ to $9&3$, for black from the $9&3$ to $1&7$.

    It is straightforward that the minimum movement we should take is shifting them all $4$ times to right or left.


    Hence, $4 times 4 = 16$ moves is the optimal one.








    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered Jan 30 at 3:31









    athinathin

    8,48522776




    8,48522776












    • $begingroup$
      that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
      $endgroup$
      – Van
      Jan 30 at 3:39


















    • $begingroup$
      that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
      $endgroup$
      – Van
      Jan 30 at 3:39
















    $begingroup$
    that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
    $endgroup$
    – Van
    Jan 30 at 3:39




    $begingroup$
    that's a much better proof than what I did - which was to sit down to a 3x3 chessboard I happened to have leftover from a woodworking project. Proof > brute force.
    $endgroup$
    – Van
    Jan 30 at 3:39











    4












    $begingroup$

    Although @athin seems to have proven it impossible, I can't find any problem with my solution in




    8 moves




    Here it is:




    enter image description here
    1. Na3 Nc3

    2. Nc1 Na1

    3. Nc2 Nb2

    4. Na2 Nb3




    Since the path is cyclic, there are working positions reached along the way too, of course.






    share|improve this answer









    $endgroup$









    • 1




      $begingroup$
      Eh, can the starting positions be different than the one given by OP?
      $endgroup$
      – athin
      Jan 30 at 6:22










    • $begingroup$
      @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
      $endgroup$
      – Bass
      Jan 30 at 6:49










    • $begingroup$
      OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
      $endgroup$
      – Chronocidal
      Jan 30 at 13:23










    • $begingroup$
      @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
      $endgroup$
      – Bass
      Jan 30 at 13:31
















    4












    $begingroup$

    Although @athin seems to have proven it impossible, I can't find any problem with my solution in




    8 moves




    Here it is:




    enter image description here
    1. Na3 Nc3

    2. Nc1 Na1

    3. Nc2 Nb2

    4. Na2 Nb3




    Since the path is cyclic, there are working positions reached along the way too, of course.






    share|improve this answer









    $endgroup$









    • 1




      $begingroup$
      Eh, can the starting positions be different than the one given by OP?
      $endgroup$
      – athin
      Jan 30 at 6:22










    • $begingroup$
      @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
      $endgroup$
      – Bass
      Jan 30 at 6:49










    • $begingroup$
      OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
      $endgroup$
      – Chronocidal
      Jan 30 at 13:23










    • $begingroup$
      @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
      $endgroup$
      – Bass
      Jan 30 at 13:31














    4












    4








    4





    $begingroup$

    Although @athin seems to have proven it impossible, I can't find any problem with my solution in




    8 moves




    Here it is:




    enter image description here
    1. Na3 Nc3

    2. Nc1 Na1

    3. Nc2 Nb2

    4. Na2 Nb3




    Since the path is cyclic, there are working positions reached along the way too, of course.






    share|improve this answer









    $endgroup$



    Although @athin seems to have proven it impossible, I can't find any problem with my solution in




    8 moves




    Here it is:




    enter image description here
    1. Na3 Nc3

    2. Nc1 Na1

    3. Nc2 Nb2

    4. Na2 Nb3




    Since the path is cyclic, there are working positions reached along the way too, of course.







    share|improve this answer












    share|improve this answer



    share|improve this answer










    answered Jan 30 at 5:09









    BassBass

    30.9k472188




    30.9k472188








    • 1




      $begingroup$
      Eh, can the starting positions be different than the one given by OP?
      $endgroup$
      – athin
      Jan 30 at 6:22










    • $begingroup$
      @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
      $endgroup$
      – Bass
      Jan 30 at 6:49










    • $begingroup$
      OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
      $endgroup$
      – Chronocidal
      Jan 30 at 13:23










    • $begingroup$
      @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
      $endgroup$
      – Bass
      Jan 30 at 13:31














    • 1




      $begingroup$
      Eh, can the starting positions be different than the one given by OP?
      $endgroup$
      – athin
      Jan 30 at 6:22










    • $begingroup$
      @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
      $endgroup$
      – Bass
      Jan 30 at 6:49










    • $begingroup$
      OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
      $endgroup$
      – Chronocidal
      Jan 30 at 13:23










    • $begingroup$
      @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
      $endgroup$
      – Bass
      Jan 30 at 13:31








    1




    1




    $begingroup$
    Eh, can the starting positions be different than the one given by OP?
    $endgroup$
    – athin
    Jan 30 at 6:22




    $begingroup$
    Eh, can the starting positions be different than the one given by OP?
    $endgroup$
    – athin
    Jan 30 at 6:22












    $begingroup$
    @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
    $endgroup$
    – Bass
    Jan 30 at 6:49




    $begingroup$
    @athin, OP seems to have given three different starting positions, and there's nothing forbidding it, so, yes, I guess?
    $endgroup$
    – Bass
    Jan 30 at 6:49












    $begingroup$
    OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
    $endgroup$
    – Chronocidal
    Jan 30 at 13:23




    $begingroup$
    OP gave 1 starting position, and 2 "almost there" positions that they were aiming at (neither of which were ever actually reached in the solution I devised - I suspect that it was "forcing" those positions that pushed OPs score up to 19 instead of 16)
    $endgroup$
    – Chronocidal
    Jan 30 at 13:23












    $begingroup$
    @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
    $endgroup$
    – Bass
    Jan 30 at 13:31




    $begingroup$
    @Chronocidal, ah, it is indeed possible to interpret "I tried the above" as meaning "I tried the above, which also had the fixed starting position below", and "position the knights" as "position the knights by moving them from the fixed starting position". Judging from OP's later edit, this might even be what OP meant. That didn't really occur to me at all.
    $endgroup$
    – Bass
    Jan 30 at 13:31











    3












    $begingroup$

    I can get you down to 16 moves. I don't know if I can do any better.



    Start off by




    moving all four corners onto the black squares, giving


    oWo


    BoW


    oBo




    Then, instead of returning to the original square, move




    them onto a corner one rotation away from where they started. This gives:



    BoB


    ooo


    WoW




    Eight moves total, so far.



    Follow the same process for four more moves, and you wind up with:





    oWo


    WoB


    oBo




    and then, four more moves (for a total of sixteen):




    BoW


    ooo


    BoW







    share|improve this answer









    $endgroup$


















      3












      $begingroup$

      I can get you down to 16 moves. I don't know if I can do any better.



      Start off by




      moving all four corners onto the black squares, giving


      oWo


      BoW


      oBo




      Then, instead of returning to the original square, move




      them onto a corner one rotation away from where they started. This gives:



      BoB


      ooo


      WoW




      Eight moves total, so far.



      Follow the same process for four more moves, and you wind up with:





      oWo


      WoB


      oBo




      and then, four more moves (for a total of sixteen):




      BoW


      ooo


      BoW







      share|improve this answer









      $endgroup$
















        3












        3








        3





        $begingroup$

        I can get you down to 16 moves. I don't know if I can do any better.



        Start off by




        moving all four corners onto the black squares, giving


        oWo


        BoW


        oBo




        Then, instead of returning to the original square, move




        them onto a corner one rotation away from where they started. This gives:



        BoB


        ooo


        WoW




        Eight moves total, so far.



        Follow the same process for four more moves, and you wind up with:





        oWo


        WoB


        oBo




        and then, four more moves (for a total of sixteen):




        BoW


        ooo


        BoW







        share|improve this answer









        $endgroup$



        I can get you down to 16 moves. I don't know if I can do any better.



        Start off by




        moving all four corners onto the black squares, giving


        oWo


        BoW


        oBo




        Then, instead of returning to the original square, move




        them onto a corner one rotation away from where they started. This gives:



        BoB


        ooo


        WoW




        Eight moves total, so far.



        Follow the same process for four more moves, and you wind up with:





        oWo


        WoB


        oBo




        and then, four more moves (for a total of sixteen):




        BoW


        ooo


        BoW








        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Jan 30 at 3:26









        VanVan

        59312




        59312






























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