Week 12 · Day 5 · 2026-10-16 FRI · CALIBRATION

Target company and cohort crosswalk

08:50-10:55 system design14:30-16:15 Backtracking20:30-21:15 recall/mock

Exact Daily Blocks

Calibrate the mechanism map for target-company style and external cohort topics while keeping the personal route independent.

08:50-10:55System design
Build the crosswalk: company emphasis, likely follow-up ladder, project retrieval rows, and opt-in cohort retrieval prompts. Do not reorder the personal sequence.
14:30-16:15NeetCode Backtracking
Exactly three unique slots; each is 30m solve + 5m evidence.
20:30-21:15Recall / mock repair
Run three 7-minute retrieval drills: storage truth, derived ranking, privacy/accountability.

DDIA decision links

Only exact Ch13/Ch14 sections that change Week 12 decisions are linked.

Decision questionExact DDIA sectionDesign consequence
What privacy boundary applies to target-company and cohort retrieval?Ch14 - 隐私与追踪The crosswalk retrieves only topic and rubric signals; it does not import private cohort transcripts into the personal route.
When is collection still unsafe even if it is useful for calibration?Ch14 - 监视Do not collect hidden behavioral traces merely to improve scoring; require visible purpose and minimization.
How does the cohort plan stay opt-in and non-blocking?Ch14 - 同意与选择自由External cohort participation creates retrieval prompts only; it cannot reorder the personal Week 12 sequence.
How is interview data reuse bounded?Ch14 - 隐私与数据使用Mock recordings, transcripts, and score notes have explicit retention, purpose, and deletion rules.

Algorithm block

Diagnostic decision: select Backtracking, not a weakest prior tag, because no production scorecard records a weaker tag and final week needs recursive state-space pruning under pressure.

SlotProblemPatternInvariantBug riskTimeSpace
13Generate Parentheses
NEW · Backtracking · 30m solve + 5m evidence
balanced DFSopen <= n and close <= open at every prefix.Closing before opening enough parens.O(Catalan n)O(n) stack + output
14Combination Sum III
NEW · Backtracking · 30m solve + 5m evidence
bounded k-sum DFSChoose k distinct numbers 1..9 with remaining sum.Missing pruning for sum or count.O(C(9,k))O(k) stack
15Factor Combinations
NEW · Backtracking · 30m solve + 5m evidence
nondecreasing factor DFSFactors are emitted in nondecreasing order.Producing permutations of same factorization.O(sqrt n branches)O(log n) stack

Output

DeliverableCohort crosswalk/retrieval plan with non-blocking rules.
Artifacts30-project map Chinese synthesis Synthesis audio English recall Recall PDF Weak repair Repair audio Cohort crosswalk
Local study materials
Detailed lecture notes, audio, recall scripts, PDFs, Staff Q&A, and mock packs are archived locally and are intentionally not published on this site.