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        riddles >> easy >> Easy: Chess Puzzle 1
        
(Message started by: ootte on Jul 24^th, 2002, 3:09am)

Title: Easy: Chess Puzzle 1
Post by ootte on Jul 24^th, 2002, 3:09am

n6r/8/8/8/7k/2b5/8/1q6

--
Oliver

Title: Re: Easy: Chess Puzzle 1
Post by jmlyle on Jul 25^th, 2002, 8:59am

Your answer violates one requirement. The top right of the center four squares needs to be attackable, and your set up doesn't do that.

I think this works:

N6Q / 8 / 8 / 8 / 7R / 2K5 / 8 / 1B6

-- jmlyle

Title: Re: Easy: Chess Puzzle 1
Post by ootte on Jul 25^th, 2002, 10:35am

on 07/25/02 at 08:59:27, jmlyle wrote:

N6Q / 8 / 8 / 8 / 7R / 2K5 / 8 / 1B6

You are right. It seems I played around with it TOO much ;)

--
Oliver

Title: Re: Easy: Chess Puzzle 1
Post by heywood on Jul 29^th, 2002, 7:12pm

I think both answers are correct! The puzzle says "can" attack on the next move, so the Q(2,8) attacks (2,1) and (6,4). The other two attacks are easily satisfied by the B(3,6) and R(8,1). N(1,1) doesnt attack and neither does K(8,5). Seems fine, am I missing something?

Title: Re: Easy: Chess Puzzle 1
Post by heywood on Jul 29^th, 2002, 7:13pm

thats an 8 not an 8)

Title: Re: Easy: Chess Puzzle 1
Post by JustMyOpinion on Aug 6^th, 2002, 1:08pm

First, Heywood's solution violates the rule that only one piece can attack square 2,1. The Q at 2,8 and the rook at 8,1 both attack the same square at 2,1. This means that there would need to be a 2 in the 2,1 square instead of a 1.

Not following all of the numbering conventions, here is my answer.
N - 1,1 (attacks none of the green numbers)
B - 2,8 (attacks 6,4 only)
K - 3,6 (attacks nothing)
R - 8,5 (attacks nothing)
Q - 8,1 (attacks 2,1 6,1 and 5,4 together)

I think this satisfies the requirements. Only one piece may attack 2,1 6,1 5,4 or 6,4 on the next move and none of them may attack 3,3.

Cheers

Title: Re: Easy: Chess Puzzle 1
Post by heywood on Aug 6^th, 2002, 3:13pm

JustMyOpinion, is my browser messed up? If you place a rook at 8,1 there is no way it can attack 2,1. There is an opponents piece located at 6,1 that is blocking that attack. Likewise, your queen at 8,1 cannot attack 2,1 since the opposing piece at 6,1 is in the way. I still think the solution I pose is correct. Help me out if I'm wrong, I play chess all the time!

Title: Re: Easy: Chess Puzzle 1
Post by John on Aug 6^th, 2002, 9:40pm

It never said that there were objects at each of the attack locations. Just that the piece could endanger that area. If you assume that there are pieces at each of the green locations, then the answer is obviously different.

Title: Re: Easy: Chess Puzzle 1
Post by heywood on Aug 13^th, 2002, 5:16pm

Oh! I just assumed there were pieces there, guess I jumped in too fast(putting too much ikea furniture together lately, no need for directions). Thanks for the help.

Title: Re: Easy: Chess Puzzle 1
Post by Elderon on Oct 11^th, 2002, 2:54pm

in the first row:
is the horsey and the queen
in the fifth row:
the tower
the sixth row:
the king
the eight row:
the last piece

Title: Re: Easy: Chess Puzzle 1
Post by shambala on Dec 24^th, 2002, 8:46pm

i got the same as Elderon...

KNIGHT (1 Left side)
QUEEN (1 Right side)
ROOK (5)
KING (6)
BISHOP (8)

Title: Re: Easy: Chess Puzzle 1
Post by SlayerWitch on Aug 28^th, 2004, 9:06pm

I have noticed that several people have posted answers on this puzzle, but no-one seems to have mentioned HOW they got to their solution. This information would be useful for two reasons:
1). To help others learn how to do this type of puzzle.
2). To prove that the solution met is the only valid solution, if there is in fact only one valid solution.
This information would also be useful to see if various people arrived at their solutions via the same or different methods.

Personally, after examing the puzzle for a while, I decided the best approach was to look at the locations that can only be reached by diagonal movement and/or knight jumping.
(NB: I numbered the blue squares 1,2,3,4 and 5 for easy reference according to their location, going from left to right, top to bottom. Likewise the green numbers are A,B,C,D and E.)
So for now I am only looking at where pieces must be placed for exactly one piece to attack each of D and E.
If 4 held the Q, then 3 would be attacked by a piece, but 3 is the '0', so therefore the queen is not at location 4. However the only way location 4 can be reached from the blue squares is diagonally, therefore there either the Q or the Bishop attacks it, thus from squares 2 or 4.
However if the B is at location 4, then either the Q must be at location 5 or the Knight must be at location 3.

If the Q is at location 5, then the Q also attacks A, which means that in order to ONLY have one piece attack square A, the piece at position 1 must be either the Bishop or the Knight, as these are the only two pieces that can attack sideways.
However since we also need a diagonally moving piece ie the Bishop, at location 4 or 2, to attack square D, we cannot have the Bishop at square 1.
So in this scenario, the Knight must be at position 1. This leaves the Rook and the King to be placed, and squares 2 and 3 to place them in.
Howver placing the Rook at space 2 does not work in this scenario since the Queen at 5 is attacking A, but a Rook at 2 would also attack A. But we cannot have the King at 2 in this scenario either, since then B will not be attacked by anything, and it must be attackable by one piece.

So we throw this theory out - there is no way the Queen can be located at square 5.

This means that the Queen must be at square 2 since we just ruled out it being at square 5, and previously ruled out it being at 4, and it must be at 2, 4 or 5, to attack diagonally.

Ok so the Queen is at square 2. Next the bishop. It must also attack a diagonally (if at all). It cannot be at 4 since it would be attacking square D as is the Queen, but it could be at location 1, or 3 and attack nothing, or at square 5 and attack square E.

Square E must either be attacked by the Bishop (which would attack from square 5), or the Knight (which would attack from square 3).
If we assume it is attacked by the Knight from 3....then squares 1 4, and 5 are left open, with the Bishop, Rook, and King left to be placed. The Bishop cannot be at square 5 with the Knight at square 5, since they would both attack square E. So where can the bishop be placed? Not at square 4 either as seen above since this would conflict with the Queen. So in this scenario, the bishop must be placed at Square 1.
The Rook and King are now left with squares 4 and 5 open. We know the Rook cannot be placed at 4, since it would attack C, the '0 attack' square, so we put the King at 4 and the Rook at 5.
Lets check that all the squares are attacked from these positions.
The Bishop doesnt attack anything, which is fine. The Queen handles squares A, B, and D, which is also fine. The Knight handles E, fine again. The King handles nothing, fine again, but wait - the Rook attacks A, which is already handled by the Queen! So again this is not a valid solution.

Therefore, we know that the Knight cannot the the piece to attack position E, so this must be done by placing the Bishop at 5.
So far what we are sure of is Queen at 2, Bishop at 5.

So, where does this leave the 3 remaining pieces?
We know that the Knight cannot be at square 3 as this would interfere with the Bishop attacking E, we know that the rook cannot be at 4 due to the '0 attack' square, and we know that neither the King not Rook can be at 1 as either piece would interefere with the Queen attacking square A.

Lets try another combination then.
From the information above, we have now deduced that the only piece that can go in square 1 is the Knight. This leaves the Rook with square 3 since it cannot be at 4, and therefore we must put the final piece, the King, in the final square, square 4.

So the recap,
Knight - Square 1, attacks nothing.
Queen - Square 2, attacks A, B, and D.
Rook - Square 3, attacks nothing.
King - Square 4, attacks nothing.
Bishop - Square 5, attacks E.

I believe from my reasoning, that this is the only valid combination for this puzzle. But feel free to use my notation system in a futher attempt to prove me wrong about this.

NB: As one poster mentioned, the puzzle does not say that there are any pieces on the board other than these 5. If you assume that there are, then of course you will get a different solution, but since the puzzle does not mention that there are any, if you assume that there are, you are really doing a different puzzle :)

NNB: Atleast 3 other people appear to have also reached this solution. Well done guys!

NNNB: I have not hidden my solution since it has already been posted in visible text more than once higher up in this thread, and since if you follow my reasoning to learn how the puzzle might be approached, you will learn of the answer that way anyway.

Title: Re: Easy: Chess Puzzle 1
Post by grandpa on Aug 29^th, 2004, 5:40am

Same problem here as I pointed out in the 'Analog Clock' thread -- what is the puzzle?

Shakespeare was reputed for his in medias res openings of plays, even scenes. Are you all trying the same dramatic device? Enlighten me, someone.
:'(

Title: Re: Easy: Chess Puzzle 1
Post by BNC on Aug 29^th, 2004, 6:00am

Hi Grandpa,

The puzzle is in the main riddle page (http://www.ocf.berkeley.edu/~wwu/riddles/easy.shtml).

(On the other hand, the forum is much more active than the "main page", so maybe we should call the forum "main page" with the riddle list a daughter page ;) )

Title: Re: Easy: Chess Puzzle 1
Post by grandpa on Aug 29^th, 2004, 9:32am

Thanks, BNC. I have sought a further clarification about this in the 'EASY: Analog Clock 1' thread.

BTW, how come all these detailed discussions of the solution aren't in the hide mode? Is it a convention here that if the actual puzzle is hidden* the answers are open, and vice versa?
(* by being tucked away somewhere else!)

Title: Re: Easy: Chess Puzzle 1
Post by towr on Aug 29^th, 2004, 1:30pm

Check the dates on the first posts of this thread :)
The hide-tags are relatively recent addition, before that it was a bit more work to hide things. And of course it took time for forum conventions to devellop.

Title: Re: Easy: Chess Puzzle 1
Post by THUDandBLUNDER on Aug 29^th, 2004, 1:42pm

on 08/29/04 at 06:00:29, BNC wrote:

(On the other hand, the forum is much more active than the "main page", so maybe we should call the forum "main page" with the riddle list a daughter page ;) )

I don't even have the 'main page' bookmarked, which means that every time somebody refers to it, I must Google it in order to find out which problem they are referring to. I think a link to it from the Forum would be very useful.

Title: Re: Easy: Chess Puzzle 1
Post by BNC on Aug 29^th, 2004, 3:23pm

on 08/29/04 at 13:42:46, THUDandBLUNDER wrote:

Try clicking "return to riddles" on the top left side (left of "home", below the forum title).