Burning Ropes Puzzle: Measure 45 Minutes with Two Non-Uniform Ropes
5 min read The Burning Ropes Puzzle: Measure 45 Minutes with Two Ropes That Burn Unevenly The burning ropes puzzle is a famous […] Read article
Brain Teasers
← techinterview
Brain Teasers
Sharpen your creative problem-solving with classic brain teasers and logic puzzles. These questions test lateral thinking, mathematical reasoning, and the ability to find elegant solutions to tricky problems.
Question Types:
Logic puzzles: River crossing, ball weighing, clock problems
Probability: Dice, cards, marbles, coin flips
Mathematical: Number sequences, geometry, combinatorics
Estimation: Fermi problems and approximations
Skills Developed:
Thinking outside the box
Breaking down complex scenarios
Finding elegant, non-obvious solutions
Communication and explanation
Interview Context: Common at Google, Palantir, and consulting firms. Tests problem-solving approach more than coding ability.
Brain Teasers, Data Structures
Building a Stack with a getMax() function
3 min read Suppose you had a Stack class. Write a new class MaxStack which, in addition to push() and pop(), has a Read article
Algorithms, Arrays, Brain Teasers, Data Structures, String Manipulation
Reverse a String
3 min read A typical programming interview question is “reverse a string, in place”. if you understand pointers, the solution is simple. even Read article
Brain Teasers, Logic Puzzles
100 Doors in a Row
3 min read Problem: you have 100 doors in a row that are all initially closed. you make 100 passes by the doors Read article
Brain Teasers, Data Structures, Dynamic Programming, Logic Puzzles
Red Marbles, Blue Marbles
4 min read Problem: you have two jars, 50 red marbles, 50 blue marbles. you need to place all the marbles into the Read article
Algorithms, Brain Teasers, Logic Puzzles
Bumblebee
3 min read problem: two trains enter a tunnel 200 miles long (yeah, its a big tunnel) travelling at 100 mph at the Read article
Algorithms, Bit Manipulation, Brain Teasers, String Manipulation
int atoi( char* pStr )
4 min read Problem: write the definition for this function without using any built-in functions. if pStr is null, return 0. if pStr Read article
Bit Manipulation, Brain Teasers, Logic Puzzles
Daughters’ Ages
3 min read Two MIT math grads bump into each other at Fairway on the upper west side. They haven’t seen each other Read article
Algorithms, Bit Manipulation, Brain Teasers, Logic Puzzles, Math Problems, Recursion
Sum it Up
4 min read Problem: you are given a sequence of numbers from 1 to n-1 with one of the numbers repeating only once. Read article
Brain Teasers, Logic Puzzles
Pirates
6 min read Five pirates have 100 gold coins. they have to divide up the loot. in order of seniority (suppose pirate 5 Read article
Bit Manipulation, Brain Teasers, Logic Puzzles, String Manipulation, System Design
Fog Creek Programmers
5 min read 100 fogcreek programmers are lined up in a row by an assassin. the assassin puts red and blue hats on them. Read article
Bit Manipulation, Brain Teasers, Logic Puzzles
Bad King
3 min read A bad king has a cellar of 1000 bottles of delightful and very expensive wine. A neighbouring queen plots to Read article
Brain Teasers
Jelly Beans
3 min read You have three jars that are all mislabeled. one contains peanut butter jelly beans, another grape jelly jelly beans, and Read article
Brain Teasers, Logic Puzzles, Microsoft Interview Questions
Bridge
3 min read Problem: this one is a classic that many of you have probably already heard, but all the more reason why Read article
Algorithms, Bit Manipulation, Brain Teasers, Logic Puzzles, Math Problems, System Design
Card Trick Without the Trick
5 min read This is a card trick without the trick. there is no sleight of hand, no tricks up my sleeve, no Read article