约瑟夫问题

这是17世纪的法国数学家加斯帕在《数目的游戏问题》中讲的一个故事：15个教徒和15 个非教徒在深海上遇险，必须将一半的人投入海中，其余的人才能幸免于难，于是想了一个办法：30个人围成一圆圈，从第一个人开始依次报数，每数到第九个人就将他扔入大海，如此循环进行直到仅余15个人为止。问怎样排法，才能使每次投入大海的都是非教徒。-Joseph problem which is the 17th-century French mathematician Gaspard is a story in the " number of game problems"　in the talk: 15 Christians and 15 non-believers in deep distress, half of the people must be put into the sea, and the rest of the people in order to survive, then thought of a way: 30 people surrounded by a circle, started from the first turn reported the number of individuals per count will be his ninth thrown into the sea, and so on until the only remaining 15 people so far . Q. How row method, in order to make each into the sea are non-believers.