Decode Ways

The Problem You have intercepted a secret message encoded as a string of numbers. The message is decoded via the following mapping: "1" → 'A' "2" → 'B' … "25" → 'Y' "26" → 'Z' However, while decoding the message, you realize that there are many different ways to decode it because some codes are contained within others (e.g., "2" and "5" vs. "25"). For example, "11106" can be decoded into: ...