Analyze Complexity From Code

Now that we've covered Understanding Big O Notation and Algorithmic Complexity, the Big O Growth Patterns Cheat Sheet, and Understanding Space Complexity, we're ready for the practical skill interviewers care about most:

Given code, can you tell how it scales?

This is different from memorizing that a pattern is O(n) or O(n^2). In real interviews, you'll often write a solution first, then the interviewer asks: "What's the complexity?"

You need a repeatable way to inspect the code you just wrote.