Red-Green-Code

Last week wrapped up the dynamic programming tutorial for this year. I hope you found it useful. Dynamic programming can be hard to grasp at first compared to other LeetCode topics. But once you internalize the steps to find a top-down solution, you may actually be happy when an interviewer asks you to solve a […]

Last week, we looked at a dynamic programming counting problem, Climbing Stairs. This week’s problem, LeetCode 91: Decode Ways, is also a counting problem. And although the problems may not seem very similar on the surface, we can adapt the Climbing Stairs solution to solve Decode Ways.

Solutions to LeetCode problems of Medium or higher difficulty often require a key insight. Even once you understand the problem and the general technique required to solve it, there’s no way to implement an efficient solution without it. Fortunately, dynamic programming gives us heuristics that we can use to point towards the required idea. For […]

Many LeetCode problems involve moving around a maze or grid. Mazes tend to be modeled as graphs, but for some problems of this type, dynamic programming is the right approach. We’ll see that in this week’s problem, LeetCode 62: Unique Paths.

LeetCode 1143: Longest Common Subsequence asks: Given two strings, return the length of their longest common subsequence. As we saw when solving the Longest Increasing Subsequence problem, a subsequence is formed by selecting elements from the input, with the only restriction being that they remain in their original order. For the LCS problem, if our […]