Week 03 — May 25–31, 2026 — Trees pt 1
Week 03 (May 25 – May 31, 2026) — TREES PT 1
13 problems (NeetCode Trees Easy + Medium). Timer on, solo, no hints until timer expires. Carry-over: SD theory (Async + Resiliency + Essentials), Drill Qs rehearsal, STAR reps. First referral DMs go out this week. Decision gate Sun May 31.
→ Full curriculum: [[Coach/project_dsa_sd_curriculum]] → Coach state: [[synthesis/Coach Hub]]
Goals This Week
- Theory block Trees fundamentals before first problem (DFS recursive, BFS iterative, BST properties) ✅ 2026-05-31
- 13 DSA problems on time, solo — timer rules same as W1/W2 ✅ 2026-05-31
- SD theory: Async Systems + Resiliency + Essentials (3 sections, ~6.75h carry from W2) ✅ 2026-05-31
- Drill Qs rehearsed: "Why leaving HCL?" + "Expected CTC?" + "2-min intro" — all 3 fluent by Wed May 27 ✅ 2026-05-31
- STAR reps: 3 minimum (WebSocket geo + AskTGE mixed)
- Referral DMs: Splunk contacts (5) + Amazon contacts (5) — sent by Sun May 31
- Sun May 31 scorecard completed + W4 direction set
DSA Problem Set (13)
Rules: timer on, no editorial/AI/peek until timer expires. One sitting per problem. Mark fail if timer expires.
| # | Pattern | Problem | LC | Diff | Target | Solved? | Time | Bugs / notes |
|---|---|---|---|---|---|---|---|---|
| 1 | Trees | Invert Binary Tree | 226 | E | 10 min | Yes | 3:00 | |
| 2 | Trees | Maximum Depth of Binary Tree | 104 | E | 10 min | Yes | 1:30 | |
| 3 | Trees | Diameter of Binary Tree | 543 | E | 15 min | Yes | 5:00 | Used list [0] for nonlocal state — prefer self.max_d or nonlocal in interviews |
| 4 | Trees | Balanced Binary Tree | 110 | E | 15 min | Yes | 5:00 | |
| 5 | Trees | Same Tree | 100 | E | 10 min | Yes | 3:40 | 3 null checks → collapse to: if not n1 or not n2: return n1 == n2 |
| 6 | Trees | Subtree of Another Tree | 572 | E | 20 min | Yes | 18:00 | Bug: split recursive calls into separate ifs → returns None. Fixed to single or return. |
| 7 | Trees | Lowest Common Ancestor of BST | 235 | M | 20 min | Yes | 7:00 | Iterative O(1) space — canonical senior solution. Prefer iterative over recursive here. |
| 8 | Trees | Binary Tree Level Order Traversal | 102 | M | 25 min | Yes | 5:00 | range(len(queue)) snapshot pattern clean. Textbook BFS level order. |
| 9 | Trees | Binary Tree Right Side View | 199 | M | 25 min | Yes | 5:00 | BFS i == size-1 pick. Know DFS alt: right-first DFS, first node at each depth = right view. |
| 10 | Trees | Count Good Nodes in Binary Tree | 1448 | M | 25 min | Yes | 7:00 | Self-corrected: nonlocal → return pattern. Use max(max_val, node.val) outside if block. |
| 11 | Trees | Validate Binary Search Tree | 98 | M | 25 min | Yes | 4:00 | Valid-range pattern. Default params expose internals — use private helper in prod. |
| 12 | Trees | Kth Smallest Element in BST | 230 | M | 25 min | Yes | 6:00 | Iterative in-order (explicit stack). Canonical. In-order = ascending in BST. |
| 13 | Trees | Construct Binary Tree from Preorder + Inorder | 105 | M | 40 min | Yes | 15:00 | nonlocal pre_idx justified (global sequential counter). Know 4-bounds canonical too. |
Score: 13/13 solved on time
SD Theory Tracker (carry from W2)
| Section | Status | Notes |
|---|---|---|
| Caching (4 topics) | ✅ Done | Carried from W2 — done 2026-05-25 |
| Asynchronous Systems (4 topics) | ✅ Done | Async Processing / Message Queues / Kafka Essentials / Real-time PubSub |
| Resiliency (5 topics) | ✅ Done | Designing for Resiliency / Load Balancers / Circuit Breakers / Data Redundancy / Leader Election |
| Essentials (5 topics) | ✅ Done | Bloom Filters / Consistent Hashing / Client-server & Protocols / Blob Storage & S3 / Intro to Big Data |
Drill Questions Tracker (carry from W2 — drafted, need rehearsal)
| Question | Drafted? | Rehearsed? |
|---|---|---|
| "Why are you leaving HCL?" | ✅ Done | ⬜ |
| "What's your expected CTC?" | ✅ Done | ⬜ |
| "Walk me through your background (2 min)" | ✅ Done | ⬜ |
Target: all 3 rehearsed fluently by Wed May 27.
BA Drills Tracker (reduced target — 3 reps/week minimum)
| Story | W2 reps | W3 target | W3 done | Notes |
|---|---|---|---|---|
| WebSocket Geo (TGE Logistics) | 3/10 | 2 reps | 0 | 250+ drivers, sub-second, hybrid hydration |
| AskTGE (DynamoDB + perf audit) | 1/5 | 1 rep | 0 | 90% token cost ↓, 50× bandwidth ↓, 2s→200ms |
Referral Outreach Tracker (W3 — first DMs)
| Contact | Source | DM sent? | Reply? |
|---|---|---|---|
| Contact 1 | Splunk conf24 | ⬜ | — |
| Contact 2 | Splunk conf24 | ⬜ | — |
| Contact 3 | Splunk conf24 | ⬜ | — |
| Contact 4 | Splunk conf24 | ⬜ | — |
| Contact 5 | Splunk conf24 | ⬜ | — |
| Contact 6 | Amazon referral | ⬜ | — |
| Contact 7 | Amazon referral | ⬜ | — |
| Contact 8 | Amazon referral | ⬜ | — |
| Contact 9 | Amazon referral | ⬜ | — |
| Contact 10 | Amazon referral | ⬜ | — |
Daily Plan
Mon May 25
- Theory block: Trees fundamentals (1.5h) — DFS recursive, BFS with deque, BST properties (valid range pattern), height vs depth, when to use iterative vs recursive
- Drill Qs rehearsal: "Why leaving HCL?" out loud x3 (15 min)
- Target: 2h
Tue May 26
- LC 226, 104, 543, 110 (4 easies, ~50 min + review)
- SD theory: Async Systems pt 1 (~1h)
- Drill Qs: "Expected CTC?" + "2-min intro" rehearsal (20 min)
- Target: 3h
Wed May 27
- LC 100, 572, 235 (3 problems, ~50 min + review)
- SD theory: Async Systems pt 2 (~1h)
- WebSocket geo STAR (2 reps)
- Target: 3h
Thu May 28
- LC 102, 199 (2 mediums, ~50 min + review)
- SD theory: Resiliency pt 1 (~1h)
- AskTGE STAR (1 rep)
- Target: 3h
Fri May 29
- LC 1448, 98 (2 mediums, ~50 min + review)
- SD theory: Resiliency pt 2 (~1h)
- Referral DMs: Splunk contacts (5 DMs sent)
- Target: 3h
Sat May 30 — Heavy day
- LC 230, 105 (2 mediums, ~1.5h + review)
- SD theory: Essentials (~2.5h)
- Referral DMs: Amazon contacts (5 DMs sent)
- LC 1448, 98 review if needed
- Target: 6h
Sun May 31 — Retro day
- Write scorecard + W4 direction (run
/coach scorecard) - SD review / catch-up if any section incomplete
- Target: 2h
Decision Gate (Sun May 31)
| Score on time | Verdict | W4 plan |
|---|---|---|
| 11–13 | Pass — strong | Trees pt 2 (Hard problems + advanced patterns) |
| 8–10 | Pass — patchy | Trees pt 2 + retry weakest Trees pt 1 problems |
| < 8 | Fail | Repeat Trees pt 1 in W4, Trees pt 2 → W5 |
Hours Log
| Day | Planned | Actual | What blocked? |
|---|---|---|---|
| Mon | 2h | ||
| Tue | 3h | ||
| Wed | 3h | ||
| Thu | 3h | ||
| Fri | 3h | ||
| Sat | 6h | ||
| Sun | 2h | ||
| Total | 22h |
Week Retro (fill Sun May 31 night)
Scorecard
- Problems solved on time: 13/13
- Total time: ~86 min vs target ~265 min (32% of allocated time)
- Weakest pattern: nonlocal mutation (LC 1448 — self-corrected mid-session)
- Strongest pattern: BFS level-order + BST traversal (all under 10 min)
SD theory completed
- Sections done: 3/3 (Async + Resiliency + Essentials) ✅
BA + Drill Qs + Referrals
- WebSocket geo reps: 0/2
- AskTGE reps: 0/1
- Drill Qs rehearsed: 3/3 ✅
- Referral DMs sent: 0/10 → CARRIED TO W4 (deadline Jun 7)
What slipped
STAR reps (3rd week running) + referral DMs (3rd week running). Root cause: avoidance, not time. "Not ready" feeling for DMs is not a real condition — no readiness threshold exists for sending a 3-sentence LinkedIn message.
What surprised me
SD theory videos require more active discipline than DSA. Sitting through video content is harder to sustain than problem-solving. Fix for W4: 25-min Pomodoro per SD topic, not marathon sessions.
W4 decision
PASS STRONG → Trees pt 2 (7 problems). Referral DMs mandatory by Jun 7. 1 paid mock scheduled.
One thing to fix in W4
Send all 10 referral DMs before W4 DSA problems start.