I’ve been delving into this fun challenge on Code Golf about converting letters to numbers and vice versa, and I’ve hit a bit of a snag that I think would create an interesting problem for everyone. So here’s the scenario:
Imagine you’re working on a simple encoding system to transform messages. Each letter of the alphabet corresponds to a number: A is 1, B is 2, C is 3, and so on, all the way to Z, which is 26. So if I have the word “CAB”, it would convert to “3 1 2”. It gets even more interesting when I want to do the reverse—taking a string of numbers like “3 1 2” and turning it back into “CAB”.
But here’s where the challenge deepens! Let’s throw in some different types of characters. For instance, if there’s a space, the output should include it in the transformation. So the phrase “HELLO WORLD” would turn into “8 5 12 12 15 0 23 15 18 12 4” with the space represented as “0”. And then if we go back the other way, we should end up neatly with “HELLO WORLD”.
Now, here’s the kicker: suppose we allow for digits in the input string too, not just letters. If the input string contains numbers, you just output those numbers as-is without conversion. For example, “A2B3” should return “1 2 2 3” upon conversion.
So, my question is: Can someone whip up a neat little solution for this that accommodates all of the above? Bonus points if it’s particularly concise or clever! It would be awesome to see how different people approach this with their preferred programming languages. Looking forward to seeing all the cool solutions!
Encoding and Decoding Letters to Numbers
Here’s a fun coding challenge! We’ve got to convert letters to numbers and back again. Here’s the breakdown:
Encoding
Each letter in the alphabet corresponds to a number:
If we take “CAB”, it becomes “3 1 2”.
Spaces are special too! In “HELLO WORLD”, the output is “8 5 12 12 15 0 23 15 18 12 4”.
Zero (0) represents the space.
And here’s the twist: if there are digits in the input, we just keep them as they are!
So “A2B3” would be “1 2 2 3”.
Decoding
On the flip side, “3 1 2” should revert back to “CAB”, and “8 5 12 12 15 0 23 15 18 12 4” should give us “HELLO WORLD”.
Sample Code Idea
Hope this sparks some ideas and you have fun trying out the challenge!
To tackle the encoding challenge where letters of the alphabet are converted to numbers (A=1, B=2, …, Z=26) while also accommodating spaces as ‘0’ and preserving digits unchanged, we can create a function that iterates through the input string. For each character, if it’s an uppercase letter, we calculate its corresponding number using the formula `ord(char) – ord(‘A’) + 1`. If the character is a space, we append ‘0’ to the result. For numerical characters, we simply append them as they are. The final output would be a space-separated string of these values, easily constructed with the `join()` method.
For the reverse transformation, we split the space-separated input and iterate through each number. If the number is ‘0’, we add a space to the result. For numbers between 1 and 26, we convert them back to letters using `chr(int(num) + ord(‘A’) – 1)`. Any digits greater than 26 can be directly appended back into our output, allowing the system to remain flexible. This approach ensures clarity and conciseness, catering to the challenge’s requirement of handling letters, spaces, and digits seamlessly.