Question

When is it appropriate to use direct addressing?

(a) When the array is comparatively large

(b) When the universe U of keys is reasonably small

(c) When the universe U of keys is reasonably large

(d) When the array is comparatively small

The doubt is from Direct Addressing Tables in portion Hash Tables of Data Structures & Algorithms I

This question was addressed to me in homework.

Answer 1

Right choice is (b) When the universe U of keys is reasonably small

The best explanation: Since each key is associated with a slot in the array, it is better to use direct addressing when the universe of keys is small as the array size grows with the increase in number of keys.