Advanced DP · Interval DP (dp[i][j] over a Range)
LC-516. Longest Palindromic Subsequence
LC-516. Longest Palindromic Subsequence on FaangDeck — Interval DP (dp[i][j] over a Range) pattern lesson. Signals, template, trap, Python solution…
What's inside this lesson
- Hook & First Instinct — frame the problem like an interviewer expects
- Brute force → Insight — what's redundant, what to exploit
- Recognition signals — three cues in the problem that point to this pattern
- Canonical template + adapted solution — clean Python, line-commented
- The trap — the near-correct bug everyone hits first time
- Trace + complexity — step-by-step walkthrough + time/space
- Interview Playbook — what to actually say in the room
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