DSA — PATTERN-DRIVEN CHECKLIST

✅ Arrays & Hashing

• [x] Two Sum (1)
• [x] Subarray Sum K (560)
• [x] Product of Array Except Self (238)
• [x] Valid Anagram (242)
• [x] Move Zeroes (283)
• [x] Rotate Array (189)

Confidence Check

• [ ] Can explain prefix sum
• [ ] Can justify HashMap usage
• [ ] Can optimize brute force

✅ Two Pointers & Sliding Window

• [x] Longest Substring Without Repeat (3)
• [x] Minimum Window Substring (76)
• [x] 3Sum (15)
• [x] Trapping Rain Water (42)
• [x] Sliding Window Maximum (239)

Confidence Check