A message containing letters from A-Z
is being encoded to numbers using the following mapping:
'A' -> 1
'B' -> 2
...
'Z' -> 26
Given an encoded message containing digits, determine the total number of ways to decode it.
For example,
Given encoded message "12"
,
it could be decoded as "AB"
(1 2) or "L"
(12).
The number of ways decoding "12"
is 2.