Decode Ways
Explore how to apply dynamic programming to decode numeric strings into alphabetic messages by counting all valid decoding combinations. Understand the problem constraints and learn to implement efficient solutions to handle strings of digits representing letters A to Z. Practice this pattern to improve your coding interview skills.
We'll cover the following...
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 following ways:
Option ...