An initiative by enjoyalgorithms! We design content with in-depth explanations and help learners develop a dedicated interest in math, logic and algorithms.

Tower of Hanoi Puzzle

Problem description of the tower of Hanoi: Given a stack of n disks arranged from largest on the bottom to smallest on top placed on a rod A, together with two empty rods B and C. The objective is to move the n disks from rod A to rod C using rod B.

The Birthday Paradox

The birthday paradox is strange and counter-intuitive. It's a "paradox" because our brain find it difficult to handle the compounding power of exponents. Real-world applications for this include a cryptographic attack called the "birthday attack".

Find out the Fastest 3 Horses

There are 25 horses among which we need to find out the fastest 3 horses. In each race, only 5 horses can run simultaneously because there are only 5 tracks. What is the minimum number of races required to find the 3 fastest horses without using a stopwatch?

Bridge Crossing at Night

A group of four people, who have one torch, need to cross a bridge at night. A maximum of two people can cross the bridge at one time, and any party that crosses (either one or two people) must have the torch with them. The torch must be walked back and forth and cannot be thrown. Person A takes 1 minute to cross the bridge, person B takes 2 minutes, person C takes 5 minutes, and person D takes 10 minutes. A pair must walk together at the rate of the slower person’s pace. Find the fastest way they can accomplish this task.

The Celebrity Problem

There are n+1 people at a party. They might or might not know each other names. There is one celebrity in the group, and the celebrity does not know anyone by their name. However, all the n people know that celebrity by name. You are given the list of people present at the party. And we can ask only one question from each one of them. “Do you know this name”? How many maximum numbers of questions do you need to ask to identify the actual celebrity?

N-Bulb in a Circle Puzzle

You have given n-bulbs connected in a circle with a switch for each bulb. The connection is such that if you change the state of anyone bulb may be on or off, it will toggle the state of its adjacent bulbs. All the bulbs are initially switched off. You have to find the number of steps such that all the bulbs are switched on.