A.先序遍歷B.中序遍歷C.后序遍歷D.層次遍歷
A.40,42,60,55,80,85B.42,45,55,60,85,80C.42,40,55,60,80,85D.42,40,60,85,55,80E.42,40,55,80,60,85
A.2n B.n C.n/2 D.n(n-1)