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Decode Ways

A message containing letters A-Z can be encoded as numbers: 'A' -> "1", 'B' -> "2", ..., 'Z' -> "26".

Given a string s containing only digits, return the number of ways to decode it.

Input:

Output:

Reasoning:

The input string 226 can be decoded as follows:
- 2 as 'B',
- 2 as 'B',
- 6 as 'F', resulting in one possible decoding: 'BBF'.
Another possible decoding is:
- 22 as 'V',
- 6 as 'F', resulting in 'VF'.
A third possible decoding is:
- 2 as 'B',
- 26 as 'Z', resulting in 'BZ'.
The total number of ways to decode 226 is the sum of these possibilities, which is $1 + 1 + 1 = 3$ .
The final output is $3$ .

Editor

Python 3.13.1

0/0

Run code to see test results.

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