Werewolf（狼人杀） is a game in which the players are partitioned into two parties: the werewolves and the human beings. Suppose that in a game,

• player #1 said: “Player #2 is a werewolf.”;
• player #2 said: “Player #3 is a human.”;
• player #3 said: “Player #4 is a werewolf.”;
• player #4 said: “Player #5 is a human.”; and
• player #5 said: “Player #4 is a human.”.

Given that there were 2 werewolves among them, at least one but not all the werewolves were lying, and there were exactly 2 liars. Can you point out the werewolves?

Now you are asked to solve a harder version of this problem: given that there were N players, with 2 werewolves among them, at least one but not all the werewolves were lying, and there were exactly 2 liars. You are supposed to point out the werewolves.

Given N rational numbers in the form numerator/denominator, you are supposed to calculate their sum.

  在算法分析课上第一次接触分支限界法（Branch & Bound），实验要求使用分支限界法解决 0/1 背包问题。虽然很清楚代码量要远高于 DP，但报告是还要写的，硬着头皮怼吧。随便在蓝桥杯题库找了一道 0/1 背包的基础题做测试，题目是算法训练的 ALGO-30 入学考试。

  Java设计模式 - 工厂模式

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