Platinum complexes containing 3-ketone cyclobutane 1,1-dicarboxylic acid as leaving group for treating cancers and a preparation method of the complexes, one of the platinum complexes is cis-3-ketone cyclobutane-1,1-dicarboxylic acid radical. A forward delay array sequentially delays an output clock signal of the delay monitor circuit to generate delay clock signals, and the mirror control circuit detects a delay clock signal synchronized with the reference clock signal among the delay clock signals. Certain non-terminating symbols are related to other non-terminating symbols.