本文发表在 rolia.net 枫下论坛1, Suppose the target ball is X, and standard ball is S. Devide the balls into 3 groups with 4 balls each, mark them as Group A, B, C;

2, Weight A versus B, for the weight there're two situations:

2.1 A and B weight the same: The ball X must in Group C, and all balls in A and B are standard balls S. Mark C balls as C1, C2, C3, C4. Weight 2 standard balls versus C1 and C2. (second pass). If C1 + C2 <> 2S. Either C1 or C2 must be X, mark them as Cx1 and Cx2; Other wise C1 + C2 = 2S, either C3 or C4 must be X, mark them as Cx1 and Cx2.

2.1.1 Weight S versus Cx1. (third pass) If Cx1 = S, then Cx2 = X ; otherwise Cx1 = X. (end)

2.2 A and B weight differently, then every ball in C is S. Mark balls in A and B as A1, A2, A3, A4 and B1...B4. Suppose A > B. Weight A1, A2, B1, B2 (AB12) versus 4S.

2.2.a If AB12 > 4S, then X is among A12 (because A>B). Mark A1 as Cx1, A2 as Cx2, goto step 2.1.1.

2.2.b If AB12 < 4S, then X is among B12. Mark B1 as Cx1, B2 as Cx2. goto step 2.1.1.

2.2.c If AB12 = 4S, then X is among AB34, and A34 > B34.更多精彩文章及讨论，请光临枫下论坛 rolia.net