Week 11 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. Binary Tree Maximum Path Sum (Week 7, Trees). https://leetcode.com/problems/binary-tree-maximum-path-sum/
  2. N-Queens (Week 9, Backtracking). https://leetcode.com/problems/n-queens/

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 a graph problem, 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”. Binary Tree Maximum Path Sum should pull back the return-vs-record split (the function returns one value to its caller, the best downward path, while a separate variable records the best full path seen anywhere); re-deriving that distinction cold, with no notes, is the test, since it is the hardest tree skill from Week 7 and you have not touched it since. N-Queens should pull back the make-choice / recurse / undo skeleton. If either one comes back slower than you expect, that is the signal for where to spend your next stretch session.