All Permutations of a String (Iterative + Recursive)

Question

## Problem

Print all permutations of a string both recursively and iteratively.

## Example
```
"abc" -> abc, acb, bac, bca, cab, cba
```

## Constraints
- 1 ≤ |s| ≤ 8

## What Cisco looks for
Be ready with both approaches and to handle duplicate characters.