Coding & Algorithms interview questions

Find the length of the longest substring without repeating characters.

Implement topological sort for a directed graph and detect if it contains a cycle.

Split array into k contiguous subarrays minimizing the maximum subarray sum (binary search on answer).

Given an m×n matrix, return all elements in spiral order.

Design a data structure that supports addNum(num) and findMedian() for a stream of numbers.

Find all starting indices of substrings in s that are concatenations of all words in any order (all words same length).

Given stock prices and at most k transactions, find the maximum profit.

Implement a data structure with insert, remove, and getRandom — all in O(1). getRandom returns a uniformly random element.

Given server logs [timestamp, server_id, start/end], find the time interval with maximum concurrent active servers. Handle 10⁸ logs efficiently.

What is the time complexity of this algorithm?

Could you write something into the object?

To clarify why I am asking: have you solved LeetCode problems, at least easy ones?

What is your algorithms experience? Have you practiced LeetCode, and do you write in Python?

What approaches are available for encoding categorical features?

Are there methods that do not depend on already having a trained model?

Where does the information encoding take place?

Instead of doing everything in a function, computing it, and putting it all into an array?

Or do we specifically need to output an array?

Under what conditions will line 17, after the loop, execute? Will it execute when we reach the last element?

Is the algorithm O(n) because we iterate over every element in the list?