One small addition: if you have the choice between a complex data structure (w/simple algo) or a complex algorithm (w/simple data structure), choose the simple

One small addition: if you have the choice between a complex data structure (w/simple algo) or a complex algorithm (w/simple data structure), choose the simple algorithm. It's very often easier to reason about data as it's relatively static, vs a complex algorithm. Once everything is working then, if it's warranted, change the algorithm.