# Twin Towers of Hanoi

## Choice of a level

Only two levels of difficulty are implemented so far: Height 2 | Height 3

#### A mild challenge

Once things start looking too easy try this version for a change. It is more difficult than it looks.

## Setting

There are two coupled sets (top and bottom set) of pegs with three pegs in each set and equal number of disks in both sets (the height of the towers). The game may be played with any number of disks (of course, it gets more difficult with more disks).

The disks in each set differ in size and no disk can be placed on top of a smaller disk on any of the pegs. Here is an example of a configuration in the game

## Moves

At any moment, there are three possible moves that may be used to change the current configuration.

• A click on the link 2-3 below the first peg (try the 2-3 link above) produces the following change in both sets. Nothing changes on peg 1, while the smallest disk on pegs 2 and 3 moves to the other peg in its own set (if it was on 2 it moves to 3, and if it was on 3 it moves to 2). Here is an illustration of the effect
Before 2-3 Click After
• Similarly, a click on the link 1-3 below the second peg changes nothing on the second peg, while the smallest disk on pegs 1 and 3 switches its position between peg 1 and peg 3 (this happens in both sets). Here is an illustration of the effect
Before 1-3 Click After
• Finally, a click on the link 1-2 below the third peg changes nothing on the third peg, while the smallest disk on pegs 1 and 2 switches its position between peg 1 and peg 2 (this happens in both sets). Here is an illustration of the effect
Before 1-2 Click After

## Object of the game

There are two version of the game. In the first the object is to reach the configuration on the right from the configuration on the left (a solution in 11 moves exist at height 3)

Start Finish

In the second version the initial configuration is chosen randomly, while the final configuration is the same as in the first.

The choice between fixed and random initial configuration is made/reset by clicking on the appropriate link at any moment during the game.