Excellent choice. Below is a daily, repeatable Focus + Recall Drill System designed specifically to sharpen attention, working memory, logical thinking, and interview-level recall.
This is practice-first, minimal theory, maximum brain impact 🧠⚡

🧠 DAILY FOCUS + RECALL DRILL SYSTEM

⏱ Total time: 45–75 minutes
🎯 Outcome: Laser focus + fast recall + strong problem-solving

🔥 PART 1: FOCUS PRIMING (5–7 minutes)

Do this before any study or problem-solving.

Drill

1. Sit straight, eyes closed
2. Breathe in 4 sec
3. Hold 4 sec
4. Breathe out 6 sec
5. Repeat × 10 rounds

✅ Clears mental noise
✅ Switches brain into deep focus mode

🧮 PART 2: MENTAL MATH DRILLS (10–15 minutes) — DAILY

🔹 Drill A: Speed Arithmetic (5 min)

Do in your head, no writing.

• 47 × 6
• 120 ÷ 8
• 19²
• 15% of 240
• 999 − 378

📌 Goal: Speed + accuracy, not perfection.

🔹 Drill B: Chain Calculations (5 min)

Start with a number, apply operations continuously.

Example:

Start = 7
× 4 → + 12 → ÷ 2 → − 5 → × 3

At the end, say the final number without retracing steps.

🧠 Trains working memory

🔹 Drill C: Estimation (5 min)

Answer approximately, fast.

• People in a football stadium?
• Books in a library?
• Seconds in a month?

📌 Interviews love estimation → this builds confidence.

🧩 PART 3: LOGIC PUZZLE DRILLS (10–15 minutes)

🔹 Drill A: Pattern Recognition

Answer mentally:

• 2, 6, 12, 20, ?
• A, C, F, J, ?
• 1, 1, 2, 3, 5, 8, ?

🔹 Drill B: Constraint Logic

Example:

3 switches control 3 bulbs in another room.
You can enter the room only once.
How do you identify which switch controls which bulb?

📌 Don’t rush — reason step-by-step aloud.

🔹 Drill C: Reverse Thinking

Ask:

• How could this fail?
• What assumption am I making?
• What if input is extreme?

🧠 This is how top problem-solvers think.

💻 PART 4: CODING THINKING DRILLS (15–25 minutes)

🔹 Drill A: Problem → Pattern (NO CODING YET)

Take any problem and answer ONLY:

1. What is the core problem?
2. Which pattern fits?
   • Hash map
   • Two pointers
   • Sliding window
   • DFS / BFS
3. What is time & space complexity?

📌 This trains interview recall, not syntax.

🔹 Drill B: Code from Memory (10 min)

• Pick a known problem
• Write solution without IDE help
• Even pseudo-code is enough

🧠 This massively strengthens recall.

🔹 Drill C: Explain Aloud (5 min)

Pretend interviewer is listening:

• Why this approach?
• Why not another?
• What are tradeoffs?

📌 If you can explain → you truly know it.

🔁 PART 5: RECALL SNAPSHOT (5 minutes)

At the end, close everything and answer:

• What math trick did I learn?
• What logic pattern appeared?
• What coding pattern did I use?

Write 3 bullet points only.

📆 WEEKLY STRUCTURE (IMPORTANT)

🧠 GOLDEN RULES

• Speed > perfection
• Recall > re-reading
• Explain > memorize
• Consistency beats intensity