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:
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.