I mean, he definitely knew about the concept of edit distance: https://en.wikipedia.org/wiki/Edit_distance before writing this code, which is the most difficult part. Here's a practice problem: https://leetcode.com/problems/edit-distance/.

So in this case, the special "something" he has is quite literally the amount of hard work he put in to learn this stuff. And if you take this opportunity to learn about edit distance, you'll be one step closer to that special someone you want to be.