Robinhood Software Engineer Onsite Coding Questions

I got the interview through a referral. Their questions were all the same ones I'd seen on forums and other sites, but I didn't pass because I felt I answered them quite well. The interviewers seemed

**Problem Statement** Exchanges only trade in whole shares, but the brokerage offers fractional shares to customers. The brokerage must manage an internal inventory to bridge this gap. The system must

Codewriting Overview: Our goal is to build a simplified version of a real Robinhood system that reads prices from a stream and aggregates those prices into historical datapoints aka candlestick charts. We\u2019re...

For onsite, I was asked an algorithms question similar to this: Users can refer each other to Robinhood. We want keep track of who is responsible for the most referrals and...

LeetCode #68: Text Justification. Difficulty: Hard. Topics: Array, String, Simulation. Asked at Robinhood in the last 6 months.

LeetCode #121: Best Time to Buy and Sell Stock. Difficulty: Easy. Topics: Array, Dynamic Programming. Asked at Robinhood in the last 6 months.

## Problem Given a list of words and a line width `W`, implement full text justification (like a word processor). Words on each line (except the last) must be spaced so the total line length equals exactly `W`. Spaces are distributed as evenly as possible; if uneven, extra spaces go to the leftmost gaps. The last line is left-justified with single spaces. ```python def full_justify(words: list[str], W: int) -> list[str]: pass ``` ## Example ``` Input: words = ["This", "is", "an", "example", "of", "text", "justification."] W = 16 Output: ["This is an", "example of text", "justification. "] ``` ## Follow-ups 1. How does your greedy line-breaking strategy perform vs. dynamic programming (Knuth-Plass)? 2. Extend to support RTL (right-to-left) text. 3. How would you handle words longer than `W`? 4. In a mobile layout context (variable-width fonts), how does the algorithm change?