Stubborn as a Programmer

Last week, Professor Danny said that a programmer always thinks his way is best. As I was working on e4b.py this week, I found that stubborn programmer mentality in myself. After reading the assignment description, I made the foolishly ambitious decision to try to program sum_to_deepest(t) my own complex way: creating a list of lists, where each inner list contained the keys in one of the paths. In doing so, I could easily just sum the longest list, and voila!

The task set before me was more difficult than expected. I tried to code multiple recursive functions, sometimes trying to return lists, and at other times trying to pass down a list that would receive elements with each function call. Nothing worked, most likely because I didn't understand Python's working of reference pointers when lists were passed down. Not only did my code not find all the paths, it also always created a messy, unexpected jumble of nested lists.

After mulling over the exercise for a few hours, going back and forth between thinking, writing, and coding, I eventually gave up and decided to do things Danny's way (that is: "define a helper function that returns both the depth of the deepest leaf and the sum along the path to that leaf.").

Using a similar structure to the preorder traversal, I only had to keep track of two integers (the sum and the path length) rather than a list and its reference pointer, which was much easier to handle. Using a dictionary to associate path lengths with the sum, I was able to easily sum the keys and access the longest path - an approach that took less than an hour to code and (most importantly) worked! All this made me realize that the stubborn programmer we often argue with is ourselves. So, the moral of the SLOG is: don't be afraid to change your approach when coding. Sometimes, a fresh perspective is the best solution!