Alice and Bob play the following coins-on-a-stack game. 20
coins are stacked one above the other. One of them is a
special (gold) coin and the rest are ordinary coins. The
goal is to bring the gold coin to the top by repeatedly
moving the topmost coin to another position in the stack.
Alice starts and the players take turns. A turn consists of
moving the coin on the top to a position i below the top
coin (0 = i = 20). We will call this an i-move (thus a 0-
move implies doing nothing). The proviso is that an i-move
cannot be repeated; for example once a player makes a 2-
move, on subsequent turns neither player can make a 2-move.
If the gold coin happens to be on top when it's a player's
turn then the player wins the game. Initially, the gold
coinis the third coin from the top
Answer Posted / teena
alice can take either a 0move or a 1 move.
initially if alice take 0 then bob take 1.. which means there are still 2 coins above the gold coin... the same is true when alice takes 1 and bob take zero...
after this alice choise must be 2.. so there is one coin above the gold coin... so then watever choice bob makes brings the coin to position 1...
ao alice is the winner
Is This Answer Correct ? | 29 Yes | 13 No |
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