1582 articles
LeetCode 516 Longest Palindromic Subsequence is the cleanest interval DP recurrence in interview prep. We derive the dp[i][j] formulation, fill the table along diagonals, and reduce memory from O(n^2) to O(n) — exactly the depth Amazon and Google look for.
LeetCode 416 Partition Equal Subset Sum is the cleanest 0/1 knapsack disguise on the platform. We reduce it to subset-sum-equals-half, derive the boolean DP recurrence, walk through the reverse-iteration trick, and finish with a one-liner bitset version that crushes interviews.
LeetCode 494 Target Sum looks like sign-assignment but reduces to subset-sum count via a beautiful algebra trick. We derive the reduction, build the 1D DP, dry-run a tabulation, and discuss why this O(n * sum) solution beats 2^n brute force at FAANG.
LeetCode 1143 Longest Common Subsequence is the foundational two-string DP every FAANG interviewer expects you to nail. We derive the dp[i][j] recurrence, walk a full table, optimize space from O(m*n) to O(min(m,n)), and trace why this template powers Edit Distance, Shortest Common Supersequence, and diff tooling.
The full 1D Dynamic Programming cheatsheet for FAANG interviews — eight pattern transitions, knapsack loop directions, LIS patience sort, and the complete problem index in one place.