All possible combinations

[hthapar]

Consider how the numbers on a mobile phone's keypad are mapped to letters. Given a number as the input, generate all possible alphabetical strings that it can represent.

If anyone can just suggest the logic and I can try myself then.

Highly Appreciated.

[helios]

http://www.cplusplus.com/forum/articles/1295/

[hthapar]

Just need some help to get started on it.

[Corpus]

A thought for a recursive solution: A set of strings for a given number N with N digits, N=N₀N₁N₂...N_k, can be seen as all possible characters for N₀ concatenated with all strings for the number N*=N₁N₂...N_k