Solution: Decode Ways
Explore how to solve the Decode Ways problem by applying dynamic programming techniques. Learn to identify valid single and double-digit mappings and use memoization to efficiently count all ways to decode an encoded digit string. This lesson helps you practice dynamic programming concepts with a practical decoding challenge.
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Statement
Given a string that has only positive digits, your task is to decode the string and determine the number of possible ways to decode it.
Consider the input string as an encoded message, where each digit in the string represents an alphabet from A to Z. For reference, let’s look at the mapping below:
"1" represents "A"
"2" represents "B"
"3" represents "C"
"26" represents "Z"
How to perform the decode operation?
To decode an encoded message, we have to check whether or not each digit in the string can be mapped onto the mapping above. There can be multiple ways to decode a string.
For example, the string "231012" can be decoded in the ...