#Hashmap

Given a list of search queries, implement a function that returns the top K most frequent queries using a frequency map (hash map). Additionally, how would you handle streaming data? What are the time and space complexities of your solution?

Given an array of integers, find indices of the two numbers such that they add up to a specific target. Implement an optimal solution using a HashMap with a time complexity of O(n).

Given a string, find the length of the longest substring that contains all unique characters. Explain your approach and provide a solution with its time complexity.

Can you explain how a hashmap works internally?

What are the advantages of using hashmaps over arrays?