Implement recursive algorithms with sub-workflows: Towers of Hanoi demo
## How it works
This is an **example of using sub-workflow nodes** and a proof of concept showing that it’s possible to **solve and explain recursive problems with n8n**.
### Towers of Hanoi - Task
Move a stack of n disks from rod A to rod C, using rod B as auxiliary. Only one disk can be moved at a time, and no disk may be placed on a smaller disk.
### Example
```
n=4
| | |
= | |
=== | |
===== | |
======= | |
--------- --------- ---------
A B C
```
### Algorithm
```
procedure Hanoi(n, X, Y, Z):
if n == 1:
move disk from X to Z
else:
Hanoi(n-1, X, Z, Y)
move disk from X to Z
Hanoi(n-1, Y, X, Z)
```
### Notes
- This is a learning example. In a real scenario, you would probably use an iterative approach with only a single code node.
- When experimenting with recursion, make sure to define a termination condition first. Also, be aware of the "Restart workspace" link in the [n8n Dashboard](https://app.n8n.cloud/manage).
- Learn more about [Recursion on Wikipedia](https://en.wikipedia.org/w/index.php?title=Recursion_(computer_science)&oldid=1301600240#Towers_of_Hanoi).
## Set up steps
- Optional: Set "*numberOfDiscs*" in node "*Set number of discs*"
- Execute workflow
