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The Stromquist three-knives procedure is a procedure for envy-free cake-cutting among three players. It is named after Walter Stromquist who presented it in 1980. This procedure was the first envy-free moving knife procedure devised for three players. It requires only two cuts, the minimum for three pieces. There is no natural generalization to more than three players which divides the cake without extra cuts. The resulting partition is not necessarily efficient. == Procedure == A referee moves a sword from left to right over the cake, hypothetically dividing it into small left piece and a large right piece. Each player moves a knife over the right piece, always keeping it parallel to the sword. The players must move their knives in a contiuous manner, without making any "jumps".〔The importance of this continuity is explained here: (【引用サイトリンク】website=Math Overflow )〕 When any player shouts "cut", the cake is cut by the sword and by whichever of the players' knives happens to be the central one of the three (that is, the second in order from the sword). Then the cake is divided in the following way: * The piece to the left of the sword, which we denote Left, is given to the player who first shouted "cut". We call this player the "shouter" and the other two players the "quieters". * The piece between the sword and the central knife, which we denote Middle, is given to the remaining player whose knife is closest to the sword. * The remaining piece, Right, is given to the third player. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Stromquist three-knives procedure」の詳細全文を読む スポンサード リンク
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