特定规则卡牌对战游戏的必胜策略问询
The contest consists of a series of matches of psychological jujitsu between bots. In each match, 2 bots face off for N = 1024 turns. At the beginning of a match, each bot receives 1024 cards numbered from 0 to 1023. In each turn, both bots fight for a number of points by playing a card, so that the one who plays the highest card wins the points. In case both play the same card, neither of them wins the points. Regardless of the outcome of the turn (even in case of a tie), both cards are discarded, so each bot must play each number from 0 to 1023 exactly once in the match. The number of points contested in each turn starts at 0 and increases by 1 until the last turn, in which 1023 points are contested.
针对这个问题,结论是:不存在能保证必胜的策略。
原因其实很直观:这个游戏是完全对称的零和博弈——两位玩家拥有完全相同的卡牌池,规则对双方完全公平,没有任何一方有先天优势。如果真的存在某个策略能让你不管对手怎么出牌都能获胜,那对手完全可以照搬这个策略反过来对付你,这就会产生矛盾:不可能双方都能保证战胜对方。
不过,我们可以找到保证至少平局的策略。比如采用“配对映射”的思路:预先把自己的卡牌和回合分值做对称配对——对于分值为i的回合,你出卡牌1023 - i,对应分值为1023 - i的回合出卡牌i。这样一来,对于每一对分值和为1023的回合(比如第0回合和第1023回合、第1回合和第1022回合),如果对手在其中一个回合赢了你,你总能在对应的另一个回合赢回来,两者的得分总和会相互抵消,最终你的总得分至少不会低于对手(大概率能达成平局)。
但要明确的是,没有任何策略能确保你一定击败所有对手,因为对手总能找到应对方式来避免输掉比赛。
备注:内容来源于stack exchange,提问作者resynel

