Someone mentioned the book Exercises in Programming Style by Cristina Lopes in Twitter and I bought it. Interesting read, can recommend. I can bring some things from the book into my course next Fall. We should actually have a course focusing mainly on these topics but alas, do not have one. I just need to implement those things I could apply in Java, maybe as demonstrations, since the book is in Python.
Another thought I need to embed into course material is this nice example of how order of things may greatly influence the time performance of code. I was evaluating a student submission of a course project. A function added nodes (unique word counts of very large text files) into a binary search tree. First a node was allocated using malloc after which the tree was searched in a loop where to put the node. And if a node with the value already existed, the frequency count of the existing node was increased and the node just created could be freed and function would return. And if the value of the node was not found in the tree, then the node just allocated was inserted into the tree in the place that was found for it. By just moving the malloc after the loop (where the node was actually needed) got rid of 30% of the execution time of the whole app. Boom! What an improvement with such a small change. Which is obvious if you have some experience but not so for many students who are in the beginning. This will be a fun demonstration…
Final thought of the day popped to my mind because of that minor piece of code having a large effect, and that is this saying:
The idiom “the straw that broke the camel’s back“, alluding to the proverb “it is the last straw that breaks the camel’s back”, describes the seemingly minor or routine action that causes an unpredictably large and sudden reaction, because of the cumulative effect of small actions.
Wikipedia