How can you read Theta straight off the loops: when do costs add, when do they multiply, and where do the six complexity classes rank?
Short drills on what this video just taught. Write the code, run the checks, and reveal the answer only if you are stuck.
The video's law-of-addition program runs one loop over range(n) and then, once that loop has finished, a second loop over range(n * n); each body only prints a letter. Define series_passes(n) that runs those same two loops, bumping a counter where each print was, and returns how many times a loop body ran in total.