Tower of Hanoi

The Tower of Hanoi (also called the Tower of Brahma or Lucas' Tower, and sometimes pluralised) 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 rules:

  • Only one disk may be moved at a time.
  • Each move consists of taking the upper disk from one of the rods and sliding it onto another rod, on top of the other disks that may already be present on that rod.
  • No disk may be placed on top of a smaller disk.

With three disks, the puzzle can be solved in seven moves.

Read more about Tower Of Hanoi:  Origins, Solution, Graphical Representation, Applications, General Shortest Paths and The Number 466/885, In Popular Culture

Famous quotes containing the words tower of and/or tower:

    With the noise of the mourning of the Swattish nation!
    Fallen is at length
    Its tower of strength;
    Its sun is dimmed ere it had nooned;
    Dead lies the great Ahkoond,
    The great Ahkoond of Swat
    Is not!
    George Thomas Lanigan (1845–1886)

    All over France, in every city there stand cathedrals like this one, triumphant monuments of the past. They tower over the homes of our people like mighty guardians, keeping alive the invincible faith of the Christian. Every arch, every column, every statue is a carved leaf out of our history, a book in stone, glorifying the spirit of France.
    Sonya Levien (1895–1960)