Merge pull request #66 from lufftw/review/pattern-interval

review(interval): Pattern quality review - Tier 2 assessment

Author: lufftw

docs/patterns/interval/templates.md

@@ -778,8 +778,6 @@ firstList = [[1,3]], secondList = [[3,5]]
 
 ---
 
----
-
 ## 7. Pattern Comparison
 
 ### 7.1 Sort Key Decision
@@ -854,8 +852,6 @@ while i < len(A) and j < len(B):
 
 ---
 
----
-
 ## 8. Decision Framework
 
 ### 8.1 Quick Reference Decision Tree
@@ -935,8 +931,6 @@ Need to INTERSECT two lists?
 
 ---
 
----
-
 ## 9. Code Templates Summary
 
 ### 9.1 Template 1: Merge Intervals (LC 56)

docs/reviews/pattern-review-log.md

@@ -49,7 +49,7 @@ This log records all pattern review findings, decisions, and resolutions. Each r
 | graph | Tier 2 | 2025-01-07 | 0/0/1/0 | Reviewed |
 | greedy_core | Pending | - | - | Queued |
 | heap | Tier 2 | 2025-01-07 | 0/0/1/0 | Reviewed |
-| interval | Pending | - | - | Queued |
+| interval | Tier 2 | 2025-01-07 | 0/0/1/0 | Reviewed |
 | interval_dp | Pending | - | - | Queued |
 | line_sweep | Pending | - | - | Queued |
 | math_number_theory | Pending | - | - | Queued |
@@ -494,4 +494,63 @@ END TEMPLATE
 
 ---
 
+## Interval Review - 2025-01-07
+
+### Files Reviewed
+- `docs/patterns/interval/templates.md` (1066 lines)
+- `docs/patterns/interval/intuition.md` (238 lines)
+
+### Reference Standards
+- Gold Standard: `sliding_window/templates.md`
+- Ontology Entries: `IntervalMerge`, `IntervalScheduling` from `ontology/api_kernels.toml`
+
+### Findings
+
+#### [INT-001]: Duplicate Section Separators
+
+| Field | Value |
+|-------|-------|
+| **Category** | Engineering |
+| **Severity** | Minor |
+| **Location** | `docs/patterns/interval/templates.md:779-781, 855-857, 936-938` |
+| **Issue** | Double `---` separators appear between sections 6-7, 7-8, and 8-9, creating visual inconsistency. |
+| **Why It Matters** | Cosmetic issue affecting document consistency. Does not impact functionality. |
+| **Decision** | Fix |
+| **Resolution** | Removed duplicate separators (3 locations). |
+
+### Positive Observations (Not Issues)
+
+| Aspect | Assessment |
+|--------|------------|
+| **API Kernel Header** | ✅ Two kernels: `IntervalMerge`, `IntervalScheduling` |
+| **Core Concepts** | ✅ Section 1 covers interval representation, sorting strategy, overlap detection, merge operation |
+| **Pattern Variants** | ✅ 5 variants: Merge, Insert, Non-overlapping, Arrows, Intersection |
+| **Code Templates Summary** | ✅ Section 9 at end with 4 templates + helper functions |
+| **Decision Framework** | ✅ ASCII decision tree (Section 8) |
+| **Sort Key Decision** | ✅ Clear comparison of "sort by start" vs "sort by end" |
+| **Visual Representations** | ✅ Excellent timeline diagrams and trace examples |
+| **"Why Sort by End?" Proof** | ✅ Greedy choice intuition well explained |
+| **Intuition Quality** | ✅ 5 mental models including "Start for Stack, End for Earnings" mnemonic |
+| **Common Pitfalls** | ✅ 3 pitfalls: wrong sort key, off-by-one overlap, not using max() |
+| **Practice Progression** | ✅ Level 1-4 problem sequence |
+
+### Summary
+
+| Category | Critical | Major | Minor | Nit | Total |
+|----------|----------|-------|-------|-----|-------|
+| Concept | 0 | 0 | 0 | 0 | 0 |
+| Explanation | 0 | 0 | 0 | 0 | 0 |
+| Engineering | 0 | 0 | 1 | 0 | 1 |
+| **Total** | 0 | 0 | 1 | 0 | **1** |
+
+### Tier Assessment
+- **Previous Tier**: Pending
+- **New Tier**: Tier 2 (Silver)
+- **Rationale**: Excellent coverage of interval patterns with two distinct API Kernels (Merge vs Scheduling). The "sort by start vs sort by end" decision framework is particularly clear. Strong intuition.md with memorable mnemonic. Minor cosmetic issue with duplicate separators.
+
+### Action Items
+- [x] Fix duplicate section separators (3 locations)
+
+---
+
 *Pattern Review Log - NeetCode Practice Framework*