圆桌放硬币
N Coins, 1 Table
题目详情
2 players take turns placing coins on a large perfectly round table. Coins can not overlap and all the coin surface must be in contact with the table. The first player who can't place a coin loses. Is it better to play first and is there a winning strategy?
解析
先手把第一枚硬币放在圆桌中心。之后对后手每一步的落子，先手在关于圆心中心对称的位置落子。
由对称性可知先手永远有合法回应，后手先无路可走，因此