A simple geometry question that fools almost everyone
(theguardian.com)
A triangle and a rectangle walked into a pub
A triangle and a rectangle walked into a pub
The largest sofa you can move around a corner
(quantamagazine.org)
A new proof reveals the answer to the decades-old “moving sofa” problem. It highlights how even the simplest optimization problems can have counterintuitive answers.
A new proof reveals the answer to the decades-old “moving sofa” problem. It highlights how even the simplest optimization problems can have counterintuitive answers.
Solving Sudoku with Tmux
(willhbr.net)
The question that everyone has been asking me since I compiled Python to run on tmux is: “can you actually do anything useful with this?”. I’m happy to report back that the answer is still no, but I can now use tmux to solve sudoku, and I can do it using a different and trickier approach than the one I used with the compiler.
The question that everyone has been asking me since I compiled Python to run on tmux is: “can you actually do anything useful with this?”. I’m happy to report back that the answer is still no, but I can now use tmux to solve sudoku, and I can do it using a different and trickier approach than the one I used with the compiler.
Explorable Flexagons: Learn to create and flex flexagons (2020)
(loki3.com)
Learn to create and flex flexagons
Learn to create and flex flexagons
From hours to 360ms: over-engineering a puzzle solution
(danielh.cc)
In January 2025, Jane Street posted an interesting puzzle:
In January 2025, Jane Street posted an interesting puzzle:
The Sudoku Affair
(explaining.software)
In 2006, Ron Jeffries wrote a series of posts describing his attempts to build a Sudoku solver.
In 2006, Ron Jeffries wrote a series of posts describing his attempts to build a Sudoku solver.
Embrace the Grind (2021)
(jacobian.org)
There’s this card trick I saw that I still think about all the time. It’s a simple presentation (which I’ve further simplified here for clarity): a volunteer chooses a card and seals the card in an envelope. Then, the magician invites the volunteer to choose some tea. There are dozens of boxes of tea, all sealed in plastic. The volunteer chooses one, rips the plastic, and chooses one of the sealed packets containing the tea bags.
There’s this card trick I saw that I still think about all the time. It’s a simple presentation (which I’ve further simplified here for clarity): a volunteer chooses a card and seals the card in an envelope. Then, the magician invites the volunteer to choose some tea. There are dozens of boxes of tea, all sealed in plastic. The volunteer chooses one, rips the plastic, and chooses one of the sealed packets containing the tea bags.
Cab Numbers
(shyamsundergupta.com)
Henry E. Dudeney [1] in his book "Amusements in Mathematics" mentions "The Cab Numbers" in the title of Problem No. 85.
Henry E. Dudeney [1] in his book "Amusements in Mathematics" mentions "The Cab Numbers" in the title of Problem No. 85.
A Puzzle about a Calculator
(aperiodical.com)
It’s now been a year since I took over the puzzle column at New Scientist and turned it into the BrainTwisters column. By way of celebration, I thought I’d write up an interesting bit of maths behind one of the puzzles, which I made a note of at the time and have been meaning to share.
It’s now been a year since I took over the puzzle column at New Scientist and turned it into the BrainTwisters column. By way of celebration, I thought I’d write up an interesting bit of maths behind one of the puzzles, which I made a note of at the time and have been meaning to share.
Build a working game of Tetris in Conway's Game of Life (2014)
(stackexchange.com)
Here is a theoretical question - one that doesn't afford an easy answer in any case, not even the trivial one.
Here is a theoretical question - one that doesn't afford an easy answer in any case, not even the trivial one.
Mathematician solves the moving sofa problem
(phys.org)
A mathematician at Yonsei University, in Korea, claims to have solved the moving sofa problem.
A mathematician at Yonsei University, in Korea, claims to have solved the moving sofa problem.
GCHQ Christmas Challenge Puzzles
(bbc.com)
Latin dancing, Indian butter and American soldiers are some of the clues for this year's cryptic Christmas challenge set by the national spy agency.
Latin dancing, Indian butter and American soldiers are some of the clues for this year's cryptic Christmas challenge set by the national spy agency.
Create your own jigsaw puzzle from any image
(puzzlezilla.com)
On this page, you can create a puzzle from any photo from the internet or your device. If you encounter difficulties, use the article on how to create your own puzzle
On this page, you can create a puzzle from any photo from the internet or your device. If you encounter difficulties, use the article on how to create your own puzzle
Fixing the Loading in Myst IV: Revelation
(medium.com)
I’ve always been a big fan of Myst. It’s a series of puzzle adventure games where you explore mysterious worlds by pointing and clicking the mouse where you want to go, solve puzzles, and discover their stories. Earlier this year, Cyan released a new remake of Riven, the sequel to Myst.
I’ve always been a big fan of Myst. It’s a series of puzzle adventure games where you explore mysterious worlds by pointing and clicking the mouse where you want to go, solve puzzles, and discover their stories. Earlier this year, Cyan released a new remake of Riven, the sequel to Myst.
Black Hole Puzzle
(wordpress.com)
101 starship captains, bored with life in the Federation, decide to arrange their starships in a line, equally spaced, and let them fall straight into an enormous spherically symmetrical black hole—one right after the other. What does the 51st captain see?
101 starship captains, bored with life in the Federation, decide to arrange their starships in a line, equally spaced, and let them fall straight into an enormous spherically symmetrical black hole—one right after the other. What does the 51st captain see?
Advent of Code 2024
(adventofcode.com)
Advent of Code is an Advent calendar of small programming puzzles for a variety of skill levels that can be solved in any programming language you like.
Advent of Code is an Advent calendar of small programming puzzles for a variety of skill levels that can be solved in any programming language you like.
Advent of Code 2024
(adventofcode.com)
Our sponsors help make Advent of Code possible: CodeCrafters.io - Build your own Interpreter, SQLite, or Git. =============== It's coding practice on steroids. ============== Try it out for free today >> =============== Bonus, solve this: PWFI YFRP, ZIK XVNVC% KTW GOXA MMQEMOTH
Our sponsors help make Advent of Code possible: CodeCrafters.io - Build your own Interpreter, SQLite, or Git. =============== It's coding practice on steroids. ============== Try it out for free today >> =============== Bonus, solve this: PWFI YFRP, ZIK XVNVC% KTW GOXA MMQEMOTH
Day 1 – Advent of Code 2024
(adventofcode.com)
The Chief Historian is always present for the big Christmas sleigh launch, but nobody has seen him in months!
The Chief Historian is always present for the big Christmas sleigh launch, but nobody has seen him in months!
Show HN: I made a calendar where every month is also a crossword
(aaronson.org)
Ever heard of the Tetris effect? It’s where you play so much Tetris that the game starts to seep into your thoughts, your dreams, your half-waking hallucinations, and pretty much every part of your reality that has nothing to do with Tetris. Well, I do a lot of crosswords—by “do” I mean both “solve” and “make”—and it turns out the “crossword effect” is also a very real thing.
Ever heard of the Tetris effect? It’s where you play so much Tetris that the game starts to seep into your thoughts, your dreams, your half-waking hallucinations, and pretty much every part of your reality that has nothing to do with Tetris. Well, I do a lot of crosswords—by “do” I mean both “solve” and “make”—and it turns out the “crossword effect” is also a very real thing.
A boy girl paradox – or maybe not?
(shankwiler.com)
The most liked comment answers 1/2, but the user got worn down by others until he recanted and agreed that the answer is 1/3. Many other comments give lengthy explanations as to why the answer is 1/3.
The most liked comment answers 1/2, but the user got worn down by others until he recanted and agreed that the answer is 1/3. Many other comments give lengthy explanations as to why the answer is 1/3.
Show HN: A simple image puzzle generator
(puzzlip.com)
Welcome to Puzzlip, it's a simple, relaxing, puzzle generator.
Welcome to Puzzlip, it's a simple, relaxing, puzzle generator.
Show HN: Knight's Graph – game based on the Knight's tour problem
(apple.com)
Step into the world of logic and strategy with "Knight's Graph," an addictive puzzle game inspired by the centuries-old knight’s tour problem.
Step into the world of logic and strategy with "Knight's Graph," an addictive puzzle game inspired by the centuries-old knight’s tour problem.
Generating Lever-Door Puzzles with JavaScript
(reconquer.online)
A lever-door puzzle is a challenge where players navigate through a series of rooms by using levers connected to various doors. When a lever is activated, it toggles the state of one or more doors. The objective of the puzzle is to progress from the starting room to a final room that holds some sort of reward.
A lever-door puzzle is a challenge where players navigate through a series of rooms by using levers connected to various doors. When a lever is activated, it toggles the state of one or more doors. The objective of the puzzle is to progress from the starting room to a final room that holds some sort of reward.
A Hamiltonian Circuit for Rubik's Cube
(cubing.net)
At last, the Hamiltonian circuit problem for Rubik's Cube has a solution! To be a little more mathematically precise, a Hamiltonian circuit of the quarter-turn metric Cayley graph for the Rubik's Cube group has been found.
At last, the Hamiltonian circuit problem for Rubik's Cube has a solution! To be a little more mathematically precise, a Hamiltonian circuit of the quarter-turn metric Cayley graph for the Rubik's Cube group has been found.