๐ผ Tower of Hanoi Guide
A simple walkthrough of rules, strategies, and tips to solve the classic puzzle efficiently.
๐ฏ Objective
Move the entire stack of disks from the left stick to the right stick, following the rules below. Middle stick is a helper stick you can use to temporarily place disks.
๐ Rules
- Move one disk at a time.
- Only the top disk of any stick can be moved.
- No disk can be placed above a smaller disk.
๐ง Core Idea (Why It Works)
The puzzle is solved by breaking it into smaller strategies. To move N disks from stick 1 to stick 3
- Move the top Nโ1 disks from 1 to 2 (using stick 3 as assistance).
- Move the largest disk (bottom one) from 1 to 3.
- Move the Nโ1 disks from 2 to 3 (using stick 1 as helper).
This is the recursive strategy and ensures minimal moves.
๐ข Minimal Moves
The minimum moves that are required to solve Tower of Hanoi with N number of disks is 2^N โ 1.
- 3 disks 7 moves
- 4 disks 15 moves
- 5 disks 31 moves
- 6 disks 63 moves
๐ ๏ธ How to Play (Step-by-Step)
For 3 Disks
- Move disk 1 to stick 3
- Move disk 2 to stick 2
- Move disk 1 to stick (on top of disk 2)
- Move disk 3 to stick 3
- Move disk 1 to peg A
- Move disk 2 to peg C
- Move disk 1 to peg C
This sequence demonstrates the pattern you will reuse for larger puzzles.
๐ก Strategies & Tips
- Always protect the largest disk: Aim to free and move the largest disk to the target peg as soon as itโs legal.
- Repeat the 3-step pattern: Move Nโ1 to helper, move largest to target, move Nโ1 to target.
- Track parity: For an even number of disks, first move to the middle peg; for an odd number, first move to the right peg (in many implementations).
- Think in chunks: Treat the top stack (Nโ1 disks) as a single unit you shuttle between helper and target.
๐ Variations
- More pegs: Some versions add a fourth peg (Reveโs puzzle) which can reduce moves.
- Timed mode: Beat the puzzle under a time limit.
- Move counter challenges: Aim for the minimal-move solution.
๐ฎ Ready to Play?
Put the strategy into practice and try solving it optimally!
Play Tower of Hanoi