I want to find all 10-key sequences that can be keyed into the keypad in the following manner:
• The initial keypress can be any of the keys.
• Each subsequent keypress must be a knight move from the previous keypress.
• There can be at most 2 vowels in the sequence.
A knight move is made in one of the following ways:
1. Move two steps horizontally and one step vertically.
2. Move two steps vertically and one step horizontally.
There is no wrapping allowed on a knight move.
A Key is allowed to be used more than once
The program should first write the number of valid 10-key sequences on a single line to standard out using C#
| A | B | C | D | E |
| F | G | H | I | J |
| K | L | M | N | O |
| | 1 | 2 | 3 | |
Sample Key Pad
A to L, L to 3
G to 2