Hello! Are you ready for an exciting journey into the world of strings and frequency analysis? Today, we’ll assist Alice, an aspiring cryptographer, with a fascinating task involving string transformations and calculations. Alice has developed a unique encoding scheme that shifts letters in the alphabet and analyzes their occurrences.
This should be a fun and insightful challenge that hones your problem-solving and coding skills. Let’s dive in!
Alice's encoding scheme involves two steps. First, she takes a word and shifts each character to the next one alphabetically. For example:
'a'
becomes'b'
'z'
becomes'a'
Next, Alice analyzes the frequency of each character in the transformed string. For each unique character, she calculates a product of its ASCII value and its frequency. Finally, she sorts these products in descending order.
Your task is to implement a Ruby method, character_frequency_encoding(word)
, that performs Alice’s encoding and returns the sorted list of products.
For example:
The method should return:
Here’s how the process works:
- Transform
"banana"
into"cbobob"
. - Calculate the products:
'c'
: ASCII value99
, frequency1
, product99 × 1 = 99
.'b'
: ASCII value98
, frequency3
, product98 × 3 = 294
.'o'
: ASCII value111
, frequency2
, product111 × 2 = 222
.
- Sort the products in descending order:
[294, 222, 99]
.
To implement Alice’s encoding scheme, we start by shifting each character to the next in the alphabet. Using Ruby’s each_char
method, we iterate over the string and transform each character.
At this stage, shifted_chars
for "banana"
will be ["c", "b", "o", "b", "o", "b"]
. This array represents the transformed characters.
Next, we calculate the frequency of each character in the transformed array. By initializing a hash with a default value of 0
, we can easily count occurrences as we iterate through the array of shifted characters.
The frequency_hash
now holds the counts of each character. For "banana"
, it will be:
Once the frequencies are ready, we calculate the product of each character’s ASCII value and its frequency. These products are stored in an array.
For the example "banana"
, the array combined_values
will contain:
Finally, we sort the calculated products in descending order to complete Alice’s encoding scheme.
This ensures the output is properly organized. For "banana"
, the sorted array will be:
Here is the full implementation of Alice’s encoding scheme, combining all the steps:
Great job! You’ve successfully implemented Alice’s unique encoding scheme. Along the way, you explored string transformations, hash frequency analysis, and sorting techniques. This exercise demonstrates how breaking a problem into smaller, manageable steps leads to clear and effective solutions.
Keep practicing, and see how far you can take these skills in future challenges!
