在n枚外观相同的硬币中，有一枚是假币，并且已知假币与真币的重量不同，但不知道假币与真币相比较轻还是较重。可以通过一架天平来任意比较两组硬币，设计一个高效的算法来检测出这枚假币。-N pieces of the same in the appearance of the coin, there is the ever- counterfeit money, counterfeit money with real money and are known to the weight of different, but I do not know the counterfeit money with real money compared to lighter or heavier. You can compare two sets of coins through an arbitrary scale, design an efficient algorithm to detect While counterfeit.