1.4.13 #

解答 #

对象的固定开销用 Object 表示。

a. Accumulator 使用 1.2.4.3 节给出的实现。

= int * 1 + double + Object * 1
= 4 * 1 + 8 + 16 * 1 = 32

b. Transaction

= string * 1 + Date * 1 + double * 1 + Object * 1
= (40 + 16 + 4 + 4 + 2N) * 1 + (8 + 32) * 1 + 8 * 1 + 16 * 1
= 128 + 2N

c. FixedCapacityStackOfStrings

= string[] * 1 + string * N + int * 1 +  Object * 1
= 24 * 1 + N * (64 + 2C) + 4 * 1 + 16 * 1
= N * (64 + 2C) + 44
= N * (64 + 2C) + 48（填充）

d.Point2D

= double * 2 + Object * 1
= 8 * 2 + 16 * 1
= 32

e.Interval1D

= double * 2 + Object * 1
= 8 * 2 + 16 * 1
= 32

f.Interval2D

= Interval1D * 2 + Object * 1
= (8 + 24) * 2 + 16 * 1
= 80

g.Double

= double * 1 + Object * 1
= 8 * 1 + 16 * 1
= 24