A.2n B.2n+1 C.2n+2 D.n+1
A.39,47,46,80,41,57 B.39,41,46,80,47,57 C.41,39,46,47,57,80 D.39,80,46,47,41,57
A.归并 B.插人 C.快速 D.选择
A.20 B.15 C.10 D.5