October 30, 2019 • ☕️ 1 min read

The Tower of Hanoi (also called the Tower of Brahma or Lucas’ Tower and sometimes pluralized) is a mathematical game or puzzle. It consists of three rods and a number of disks of different sizes, which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape.

The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:

- Only one disk can be moved at a time.
- Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack or on an empty rod.
- No disk may be placed on top of a smaller disk.

Animation of an iterative algorithm solving 6-disk problem

With `3`

disks, the puzzle can be solved in `7`

moves. The minimal
number of moves required to solve a Tower of Hanoi puzzle
is `2^n − 1`

, where `n`

is the number of disks.