This " method of construction " ( realized through the method of completing square ) is far conciser than my classification method and i feel pleasantly surprised at the beauty of concision from the standard solution 這個"構(gòu)造法" (通過配方法實現(xiàn)) ,比我采用的分類處理法不知要簡潔多少倍,標(biāo)準(zhǔn)解答所散發(fā)的簡潔美令我感到驚喜。