☕ Microsoft bets big

A Google Interview Question. Microsoft bets big with OpenAI. Pinterest sees crazy growth due to iOS 14. A new gaming startup raises money.

Good Morning Planet Earth!

Hope you’re all having a fantastic day.

Here’s your interview problem and industry news!

Interview Problem

Write a program that solves a Sudoku puzzle by filling in the empty cells.

You’ll be given a 2-D array that represents a Sudoku board. The board will contain only the digits 1 - 9 or empty strings that represent spaces. The board will always be 9x9.

Fill in the empty spaces with integers to generate a valid Sudoku board and return the completed 2-D array.

A valid Sudoku board satisfies…

  1. Each of the digits 1 - 9 must occur exactly once in each column.
  2. Each of the digits 1 - 9 must occur exactly once in each row.
  3. Each of the digits 1 - 9 must occur exactly once in each of the nine 3 x 3 sub-boxes in the grid.

We’ll send out the solution (with working code & test-cases) tomorrow, so make sure you move our emails to primary, so you don’t miss them!

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Industry News

  • Microsoft gets an exclusive license for OpenAI’s GPT-3 Model - GPT-3 is a language model developed by OpenAI, and it’s been extremely impressive so far. People have used the language model to write poetry, JavaScript code, long-form news articles and even jokes (funny ones!). The way language models work is that they look at the past sequence of characters and use that to generate a probability distribution on what the next character will be. It uses its prediction to generate the next character and then repeats the process. GPT-3 is a language model with 175 billion parameters. Prior to GPT-3, the largest language model was Microsoft’s Turing NLG, with 17 billion parameters.Now, Microsoft has announced that it will exclusively license GPT-3 and use it to deliver AI solutions for customers through Microsoft’s Azure platform. The implications of the licensing agreement aren’t clear, but Microsoft says that OpenAI will continue to offer GPT-3 through their own API. To be clear, OpenAI’s partnership with Microsoft has been going on for a while; Microsoft invested $1 billion dollars into the company last year.
  • Pinterest breaks daily download record due to…. iOS 14 - With the launch of iOS 14, there’s been a massive excitement around the ability to customize your iPhone’s home screen. This is just one of the many new features in the new version of iOS, that has made it very popular (we talked about this in one of our last issues!).Many iPhone users are now using Pinterest for design inspiration like photos for custom app icons or wallpapers. This has led to Pinterest’s app seeing a record global daily number of downloads and a rapid climb up the App Store’s Top Charts. According to Apptopia, Pinterest saw approximately 616,000 downloads on September 21st.
  • Manticore raises $15 million dollars in funding from Epic Games - Manticore is a new gaming startup that allows users to build high-resolution multi-player desktop games. According to CEO Frederic Descamps, “It’s a new type of platform where you have players congregating to create worlds together, to create a new form of entertainment”.It’s similar in some respects to Minecraft or Roblox, but Manticore is targeting an older audience. It’s positioning itself as a place to build games for teens and adults and wants its creators to utilize revenue-sharing deals, similar to what Roblox uses.The company has raised $45 million since launching in 2017, so looks like they certainly have a nice runway to implement their vision!

Previous Solution

As a reminder, here’s the previous question

Given an integer, write a function to determine if the integer is a power of two.

Try to do this in O(1) time.


This is one of those questions where you either know it, or you don’t.

If you know how Bit Manipulation works, then this question is pretty trivial.

If you don’t, then you should learn how Bit Manipulation works!

Here’s the best video I’ve seen that explains the core of Bit Manipulation.

The video also goes over this question!

The question can be solved with this expression

n & (n - 1) == 0 # if this is true, then n is a power of 2

However, this expression fails in one case.

Can you identify it?

Once you figure it out, check out our solution.

Thanks for reading this edition of the Quastor Daily Interview Problem.

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