h*******r
发帖数: 207 | 1 I was asked several days ago this classical brainteaser for an HF onsite
interview. I know the answer but do not know why. Anyone can give a detail
solution about it?
For a 3*3*3 cube, you remove side cubes one by one. Can you leave the center
cube as the last one to remove? |
I***e
发帖数: 1136 | |
b***k
发帖数: 2673 | |
I***e
发帖数: 1136 | 4 Sorry wrong reference. Here is another try:
Color all pieces black or white with alternating colors. If the center piece
is black, then there must be 12 blacks other than the center piece. And 14
whites other than the center piece. Therefore, you can not do the removal
because each two removals must be one black and one white.
-iCare- |
s*********l
发帖数: 103 | 5 http://spellscroll.com/questionfull/286/
pcasnik said at 2009-06-11 02:41:02:
what does it exactly mean by "remove side cubes one by one"?
center
【在 h*******r 的大作中提到】
: I was asked several days ago this classical brainteaser for an HF onsite
: interview. I know the answer but do not know why. Anyone can give a detail
: solution about it?
: For a 3*3*3 cube, you remove side cubes one by one. Can you leave the center
: cube as the last one to remove?
|
c******j
发帖数: 149 | 6
center
起始点的坐标是(1, 1, 1), center cube的坐标是(2, 2, 2), 两个坐标的和都能被3整
除, 但是从头到尾要走25步, 25不是3的倍数, 所以不可能.
【在 h*******r 的大作中提到】
: I was asked several days ago this classical brainteaser for an HF onsite
: interview. I know the answer but do not know why. Anyone can give a detail
: solution about it?
: For a 3*3*3 cube, you remove side cubes one by one. Can you leave the center
: cube as the last one to remove?
|
