El-Kebir et al. 建立基因複製樹問題,並證明其為NP-hard。我們發現該證明並不正確。我們對該問題做了若干修改,並探討其NP-hardness性質。 El-Kebir et al. established the copy-number tree problem and proved it to be NP-hard. We found that the proof is not exactly correct. Thus, we have made some changes to this problem and discuss its NP-hardness property.