flipping of coins

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flipping of coins

Post  ankurgutpa on Mon Aug 11, 2008 9:32 pm

There is a black table such that u can't see what is inside it..It contains 4 coins placed in at 4-different directions(north, east, south, west).You have to make all the coins facing towards head.
You can do following operations:
1. Flip any one coin.
2. Flip adjacent coins.
3. Flip diagonal coins
4. Flip all coins.

After your every answer table makes a random number of rounds(so u r not sure which coin was flipped previously)

Also after every flip u can ask a question whether all points are facing head...(if all coins are facing head u will get 'yes' as an answer else 'no') cheers

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Re: flipping of coins

Post  fault++ on Tue Aug 12, 2008 2:37 pm

ankurgutpa wrote:There is a black table such that u can't see what is inside it..It contains 4 coins placed in at 4-different directions(north, east, south, west).You have to make all the coins facing towards head.
You can do following operations:
1. Flip any one coin.
2. Flip adjacent coins.
3. Flip diagonal coins
4. Flip all coins.

After your every answer table makes a random number of rounds(so u r not sure which coin was flipped previously)

Also after every flip u can ask a question whether all points are facing head...(if all coins are facing head u will get 'yes' as an answer else 'no') cheers

phadu haibe be No

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HECK !!!!

Post  Dee2306 on Tue Aug 12, 2008 3:31 pm

I Dont think you should expect any answers... unless this ques. starts making any sense... Shocked
wat Inside the table..and hw the coins are placed..in different directions...Are their HEADS towards the respective directions or wat ??

bounce ==>> Can u Explain a Lil' More.. lol!

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Re: flipping of coins

Post  ankurgutpa on Tue Aug 12, 2008 5:49 pm

what i interpreted from the question is:
coin are placed like this
...*
* ..... *
...*
now u don't know whether the head or tail on upper side.
now apply any of the four operation to make them all head by considering above constraint cheers

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Re: flipping of coins

Post  shivang on Tue Aug 12, 2008 9:40 pm

neat question buddy.....
just try n give a hint Twisted Evil cheers

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My Solution:

Post  Ramprasadg on Wed Aug 13, 2008 9:14 pm

my convention
1) '-' represents check/ask the question
2) each number represents the operation as specified in the question

actual solution:
the sequence of operations is
-4-3-4-2-4-3-4-1-4-3-4-2-4-3-4-

before this sequence ends, u will be able to arrange all the coins in a heads up manner.
if u want check with real coins,i myself tried many times.it seems to work.

explanation:
north,south,etc ... are of not that importance because the table may be spun(to any no of times).
there are basically 6 different arrangements(states) namely
1)4 Heads(final state)
2)4 Tails
3)2 Heads 2 Tails diagonally arranged(meaning same type on diagonally opp).
4)2 Heads 2 Tails adjacently arranged.
5)3 Heads 1 Tail
6)1 Head 3 Tails

the above order is more or less the closeness to the final state that is 1.
i will try and upload a diagram showing the transitions ...it looks similar to the Automata theory state diagrams(not sure if it can be called a transition diagram)

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series rply

Post  vivek.nuna on Thu Aug 14, 2008 4:24 am

1,0,3,4,27,115,728,5027.......
so terms r lyk 0!+0,1!-1,2!+1,3!-2,4!+3,5!-5.........
so next term ll be 8!+21

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solution:flipping of coins

Post  tirth on Thu Aug 14, 2008 1:03 pm

my solution is also sumwt similar to that posted by ramprasad.....and it definitely does work

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Re: flipping of coins

Post  ankurgutpa on Sat Aug 16, 2008 12:06 pm

you are correct RamP
u hv implemented Automata in the best way cheers

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