Real Exams

For 2024

Meta

• Simple simulation
• Mathematical Coding with Text Splits + Variable Length Suffix
• Mathematical Coding with finding triplets
• Mathematically splitting arrays

Belvedere Trading (SWE)

• Determining the Stock Performance Score from a Continuous Stream of Trades.
• Creating a Buy-Sell Ladder from a Continuous Stream of Trades.
• Determining to Buy or Pass a Stock Bundle, given the market prices.

IXL

• Find the Largest Common Divisor with Minimum Increments
• Anagram Difference
• Mathematic Programming
• Find the longest consecutive elements after element deletions

IBM

• Minimum number of machines required to finish the task, given start times and end times (Sort by start time, then use end time min heap)
• Minimize $\sum_{i=1}^{\texttt{len}(\texttt{arr})-1} (\texttt{arr}_i - \texttt{arr}_{i-1})^2$ (Find the max gap and then insert the avg in between)

Belvedere Trading (Analyst)

• Sliding window (but both in traded stock count and trade history count) Stock price average finder
• Linear Regression (Scikit)

Goldman Sachs

• Sliding Window
• Given a sequence of moving commands, is there a loop?

Optiver

• Retain $N$ logs. recordLog(self, logId, timestamp), getLogs (self), getLogCount (self) Simulations, sliding window
• Calculate stock price, given dividend payout on specific dates. Dividend payouts are editable. Simulations

MathWorks

• The maximum minimum element after $k$ decrements. Optimized Simulations
• Construct a graph and traverse it to find the $\text{MaxBeauty}$, where $\text{Beauty}$ for node $k$ is $\sum_{i=0}^{N} \text{distance}(i, k) \times \text{value}(k)$

Citadel

• Find max increasing subarray, but in two arrays
• Chess Move BFS

Ramp

• Let's make a storage ownership system
• Count $N$ largest files
• Make it support many users (each has its storage limit), including root
  • Merge them
• Cloud Backup & Restore

For 2023

PayPal

• 1 Simulations
• 1 Optimized Simulations (prefix array)

PathAI

• 1 Simulations that had a bunch of edge cases (solved 9/10)
• 1 Optimized Simulations

Grammarly

• 1 Simulations
• 2 Optimized Simulations

Duolingo

• 1 multiple map problem (simple data analysis & processing)
• 1 path reduction problem (didn't have enough time)

LinkedIn

• 1 Optimized Simulations
• 1 Mathematic Programming

Akuna Capital — "Front Runner"

• 1 Optimized Simulations
• Passed 5/8 test cases

DRW

• 2 Optimized Simulations
• 1 Greedy Algorithm

Akuna Capital Python

• 1 Optimized Simulations
• 1 text compression & Optimized Simulations
• 1, which seemed Greedy Algorithm (I didn't have the time to solve it)

Akuna Capital C++

• 10 multiple choice questions
  • required a deep understanding of C++ recent specs
• 1 Greedy Algorithm palindrome substring search
• 1 adjacency list construction and tree search.
  • Time limit was stringent, and I wasn't able to finish it
• 1 Optimized Simulations using bitwise operations
  • Time limit was stringent, and I wasn't able to finish it

Valkyrie Trading

• 1 binary tree construction & Binary Search traversal
• 1 Simulations

CodeSignal (HRT, Databricks

• 2 Simulationss
• 2 Optimized Simulationss

IMC

• 1 BFS
• 1 Optimized Simulations

Garda Capital Partners

• 3 Mathematic Programming problems (2 finding-formula, 1 map)
• 1 SQL Problem

BlackRock

• 1 stack
• 1 BFS

For 2022

Facebook

• 1 recursion
• 1 simple algorithm
• 1 Optimized Simulations

Coinbase

• 1 Mathematic Programming
• 1 Optimized Simulations

Goldman Sachs

• 1 Mathematic Programming
• 1 Optimized Simulations

Sezzle

• Get Job Done SQL, React, Python

Twitch

• Get Job Done Data Parsing

Bloomberg

• BFS