Week 9 Cold Revisit

This Friday, before any new work, re-solve two prior problems cold: no notes, no prior code open, no AI, the standard 25-minute struggle floor on each. The first solve taught the pattern; this blind re-solve is what makes it stick.

The two problems

  1. Koko Eating Bananas (Week 5, Binary Search). https://leetcode.com/problems/koko-eating-bananas/
  2. Maximum Depth of Binary Tree (Week 7, Trees). https://leetcode.com/problems/maximum-depth-of-binary-tree/

How to run the revisit

  • Do not look up which pattern either problem belongs to. Recognizing it cold, from the problem statement alone, is the entire point of the exercise; the tutor will not tell you.
  • Start each from a blank file. Name the pattern aloud, write the plain-English approach as a comment, then code.
  • Apply the 25-minute floor to each independently. If you stall past the floor, use the hint ladder, one rung per ask.
  • Submit each to LeetCode’s judge. The judge is the oracle, not the tutor.
  • Debrief each with the five questions in your commit message, and log the outcome in .tutor/revisit-log.md.

Neither problem is backtracking, and that is deliberate. The cold revisit trains recognition across the whole course, so the muscle you build is “read a cold statement and feel the pattern”, not “apply this week’s pattern again”. Koko is “binary search on the answer”, where you search the eating speed and test a monotonic feasibility predicate; Maximum Depth is a small tree recursion whose return-value shape (one plus the deeper child) you should be able to rebuild without hesitation. If either one comes back slower than you expect, that is the signal for where to spend your next stretch session.