A.n2/2+2n的漸進表達式上界函數(shù)是O(2n) B.n2/2+2n的漸進表達式下界函數(shù)是Ω(2n) C.logn3的漸進表達式上界函數(shù)是O(logn) D.logn3的漸進表達式下界函數(shù)是Ω(n3)