Describe a set. Provide a a code snippet with common operations.

Describe dictionary. Provide a a code snippet with common operations.

Describe a hashing technique.

Assume that the set s contains the number $3.$ Write the sequence of sets $($for each line below$)$ resulting from the following operations:

s$.$add$(4)$

s$.$add$(4)$

s$.$add$(5)$

s$.$remove$(3)$