Logical puzzles and challenges

33 27,655 739
articles words lines of code
N queens problem

This article shows how to solve the N queens problem in 20 lines of code.

algorithms combinatorics logic programming python recursion
Problem #064 – infinite mathematicians with hats

How can an infinite number of mathematicians figure out their own hat colours?

logic mathematics sequences
Problem #063 – arbitrarily many primes in arbitrarily big intervals

Can you prove that there are arbitrarily many primes in arbitrarily big intervals?

logic mathematics number theory primes
Problem #062 – sliding coins

Can you align all of the coins on the right edge of the board?

invariants logic mathematics
Problem #061 – flower garden

Three mathematicians discuss a beautiful flower garden and the coloured flowers within.

logic mathematics
Problem #060 – realtor commissions

Two realtors discuss who's netting the award for highest average commission, but it isn't clear who the winner is...

logic mathematics
Problem #059 – marching pegs

How can you swap the coloured pegs if they can only march forward?

logic mathematics
Problem #058 – identifying light bulbs

Please help me identify these 100 light bulbs by turning ON and OFF their switches.

binary logic mathematics
Solving Wordle with APL

Join me in solving the word game Wordle in (Dyalog) APL.

apl game logic programming
Look-and-say sequence

We discuss the look-and-say sequence, its behaviour, variations of it, and a Python implementation.

logic mathematics programming python sequences
TIL #038 – look-and-say sequence growth

Today I learned that the length of the terms of the “look-and-say” sequence has a well-defined growth rate.

logic mathematics sequences
Problem #055 – horse racing

25 horses racing, and you have to find out the fastest ones!

logic mathematics
Problem #053 – weighing the odd one out

Can you find the fake ball by weighing it?

logic mathematics
Solving Wordle with Python

In this article we try to crack Wordle, a variation of mastermind played with (English) words.

game logic programming python
Problem #048 – trick or treat

Can you help these kids trick or treat their entire neighbourhood in this Halloween special?

combinatorics logic mathematics probability
Problem #047 – surgery gloves

How can two doctors operate two patients with only two pairs of latex gloves?!

logic
Problem #045 – 1, 2, 3

Figure out the number I'm thinking of with a single question!

logic mathematics
Problem #044 – send more money

Can you solve this simple-looking arithmetic challenge?

arithmetic logic mathematics
Problem #043 – Rubik's cube scrambling

If I scramble a Rubik's cube for long enough, will it solve itself?

combinatorics group theory logic mathematics
Problem #042 – mine captcha

Can you solve this little minesweeper puzzle?

game logic mathematics