How to tell which dynamic programming pattern a problem wants
7 min read A reference to the main dynamic programming families, what the dp array means in each, and the canonical problems that drill each one. Read article
Algorithms
Coding Interview Questions
How the edit distance table fills itself in
6 min read A walkthrough of LeetCode 72, from the recursive prefix idea to the 2D table, its O(n)-space version, and the follow-ups interviewers ask. Read article
Coding Interview Questions
Solve House Robber with two numbers and a state machine
7 min read House Robber reduces to two running numbers and a two-state machine, and that same shape solves the circular, tree, and stock-cooldown follow-ups. Read article
Coding Interview Questions
How Kadane’s algorithm finds the maximum subarray in one pass
6 min read Kadane’s algorithm finds the largest contiguous subarray sum in a single pass, and the interview really lives in the follow-ups: all-negative inputs, returning indices, and the product and circular variants. Read article
Algorithms
The seven DP recurrences that cover most interview questions
7 min read The seven recurrences that cover most interview dynamic programming, with the tells that let you recognize each one before you write code. Read article
Coding Interview Questions
The trick to Word Break is spotting the repeated work
6 min read Word Break looks like a string problem but rewards you for caching subproblems by start index, from the memoized recursion to the trie follow-up. Read article
Coding Interview Questions
Why greedy fails on Coin Change, and the DP that fixes it
5 min read Greedy returns the wrong coin count the moment denominations aren’t standard, so Coin Change needs a short dynamic-programming table instead. Read article
Coding Interview Questions
Trapping Rain Water, from brute force to two pointers
6 min read The trapped-water problem has three standard solutions, and the gap between them is what an interviewer is actually grading. Read article
Dynamic Programming
0/1 Knapsack Problem: DP Solution with Space Optimization
3 min read The 0/1 Knapsack problem is one of the most important DP patterns. Unlike coin change (unbounded knapsack), each item can Read article
Dynamic Programming
Longest Common Subsequence: DP Solution and Space Optimization
3 min read Longest Common Subsequence (LCS) is a fundamental string DP problem that appears in interviews at Google, Microsoft, and Amazon — Read article
Dynamic Programming
Edit Distance (Levenshtein): DP Solution Explained
3 min read Edit Distance (Levenshtein Distance) is a classic string DP problem that appears in interviews at Google, Microsoft, and Dropbox. It’s Read article
Dynamic Programming
Word Break Problem: Dynamic Programming Solution
2 min read Word Break (LeetCode 139) is a string DP problem that tests whether you can partition a string using a given Read article
Dynamic Programming
Coin Change: Bottom-Up and Top-Down Dynamic Programming
2 min read Coin Change (LeetCode 322) is the canonical dynamic programming problem. It tests your ability to identify optimal substructure, choose between Read article
