What is time and space complexity of Dictionary?

Question

Let's assume I have data of size N (i.e.N elements) and the dictionary was created with capacity N. What is the complexity of:

• space -- of entire dictionary
• time -- adding entry to dictionary

MS revealed only that entry retrieval is close to O(1). But what about the rest?

Answer 1

The time complexity of adding a new entry is documented under Dictionary<T>.Add():

If Count is less than the capacity, this method approaches an O(1) operation. If the capacity must be increased to accommodate the new element, this method becomes an O(n) operation, where n is Count.