简介:Inthispaper,byvirtueofthecombinatorialoptimizationandgrouptestingmethodand,withascalewithoutweight,wedetectncoinscontainingatmostoneabnormal.Thencoinsareindistinguishableonlybytheirappearances.Wederiveanoptimalprocedureofdeterminingwhetherallthenballsarenormalornotandinthelattercase,ourprocedure(algorithm)alsotellswhethertheabnormalweighsmoreorweighslessthaneachofthenormals.Theoptimalalgorithmobtainedinthispaperisconstructive.