Feature #6: Combine Similar Messages

Description

Someone is posting messages on Facebook that are apparently gibberish. Research has indicated that the author picks every word and mutates it by adding a fixed offset value to each letter in the word. For example, they may mutate hy to iz by adding 1 to each letter of hy. Similarly, they may mutate hy to ja by adding 2 to each letter of hy, etc. We want to decode these messages. The first step is to group all the words that may be mutations of each order to make further analysis easier.

We’ll be provided with a list of strings in which each string represents a garbled message. Our task is to group all the messages that differ by the same number of offsets in each of their characters.

Here is an illustration of this process:

Solution

From the above example, we can see that the difference between consecutive characters of each word is equal for each set. Consider the words lmn and mno from Set 1 of the example above. The difference between the ASCII values of each pair of consecutive characters of lmn is (1, 1), respectively, and the difference between each character of mno ...