Box ‘o Numbers
Arrange the numbers 1 to 8 in the grid below such that adjacent numbers are not in adjacent boxes (horizontally, […]
Arrays
Brain Teasers, Logic Puzzles
Coin Problem
some of you may have easily solved the pill weighing problem posed here. If so, you are going to love
Coding Interview Questions
Parallel Lines
Solution Not really much to solve 🙂 2026 Update: Parallel Lines — Geometry Algorithms and Line Intersection Determining if lines
Coding Interview Questions
Moving Circles
Solution You may be able to find the solution on the discussion forum. 2026 Update: Collision Detection — Computational Geometry
Coding Interview Questions
Black Dots
Solution You may be able to find the solution on the discussion forum. 2026 Update: Gestalt Perception and Counting Algorithms
Brain Teasers, Dynamic Programming
X Implies Y
Part I (you can’t use paper, you have to figure it out in your head) i have a black triangle,
Bit Manipulation
XOR using NAND gates
Create an XOR gate using only NAND gates. (BTW, mostly all circuit problems assume you have two inputs plus 0
System Design
Smart Cookie
Did you ever wonder how they make those pillsbury cookie dough rolls with the intricate faces inside them? Look here and
Data Structures
Wanna Play?
I offer to play a card game with you using a normal deck of 52 cards. the rules of the
Math Problems
Crazy Guy on the Airplane
A line of 100 airline passengers is waiting to board a plane. they each hold a ticket to one of
Coding Interview Questions
Chameleons
At one point, a remote island’s population of chameleons was divided as follows: 13 red chameleons 15 green chameleons 17
Brain Teasers, Logic Puzzles
Railroad Bridge
A man needs to go through a train tunnel. He starts through the tunnel and when he gets 1/4 the
Math Problems
Cars on the Road
if the probability of observing a car in 20 minutes on a highway is 609/625, what is the probability of
Algorithms, Logic Puzzles
Switches
The warden meets with 23 new prisoners when they arrive. He tells them, “You may meet today and plan a
Brain Teasers, Logic Puzzles
Yarr Maties
Five pirates discover a chest full of 100 gold coins. The pirates are ranked by their years of service, Pirate