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BST

AVL

search: $\theta(height)$

insert: $\theta(height)$

delete: $\theta(height)$

Worst case cost for all operations is $\theta(height) = \theta(log \space n)$

Other Dictionary Implementations

Dictionary ADT

If a graph in which every vertex has degree k, for some fixed k, is called a k-regular graph (or a regular graph)

The number of vertices of odd degree in a graph is even.

ARC stands for Automatic Reference Counting. It manages memory. Only if reference counting becomes 0, memory will be deallocated.

When it compiles

ARC counts when it compiles, so it’s easy to predict when the instance memory will be deallocated, but that also means there is a chance that instance never deallocated in memory.

GC counts when the program runs, so it reduces performance as we need more resources to count references and in contrast to ARC it’s hard to predict when the instance will be deallocated from memory. However, we have more opportunity to deallocate memory even in complex situation and do not need to worry about such rules.

Strong owns object and reference count will increase. Retain when assigned and Released when counting ends.

Weak does not own object but only have address, just like point. Although weak does do refer to some object, it can’t deallocate the object. Thus, there is no retain or therefore release. So, we don’t know when and how this memory will be used or deallocated. But once if the memory released, ARC will change this reference to nil. That means, weak object should be optional.

Delegate pattern.

향후 쓰일 기술이 무엇이 있을까 고민을 해보자. 아래의 조건을 충족하는 기술들. 그러나 회사(주식)에 국한되지 않게 생각을 해보자. 원초적으로.

저 문장을 조금 더 깊게 파고 들어가보자.

현재에 대해 초점을 맞추어서 고민해보자.

변화에 초점을 두어서 고민해보자.

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