interviews

Learn how to achieve O(1) insert, delete, and getRandom operations using a HashMap and ArrayList with the swap-with-last technique. Optimize your collection performance.

Explore backtracking and bit manipulation methods to generate all subsets of an array. Learn efficient recursive and iterative techniques for subset generation.

Solve the Paint House II problem efficiently with dynamic programming. Discover the O(nk) time and O(1) space solution by tracking minimum costs. Learn the optimal approach now.

Learn the dynamic programming solution for the Decode Ways problem. Efficiently count valid letter interpretations of numeric strings in O(n) time using tabulation and a clear guide.

Learn to implement wildcard pattern matching for strings in Java. Explore Trie and Dynamic Programming solutions for single-character and regex patterns from the kdn251/interviews repo.

Calculate product of array except self in O(n) time and O(1) space using a two-pass algorithm without division. Learn the efficient Java solution.

Master the algorithm for merging overlapping intervals with this greedy implementation guide. Achieve O(N log N) efficiency by sorting and combining.

Implement an LRU Cache in Java with O(1) time complexity. Combine HashMap and doubly-linked list for efficient get, put, and eviction operations. Master cache implementation.

Learn to find the number of islands in a 2D grid using DFS or BFS. Discover efficient graph traversal techniques to count connected land components and avoid double counting.

Learn to solve the Word Break problem efficiently using DP and Trie. Achieve O(n·L) time complexity for faster solutions.

Master regular expression matching with dynamic programming in Java. Build an O(m x n) DP table to handle . and * efficiently. A complete guide for interviews.

Learn the dynamic programming solution for the House Robber problem. Discover how to maximize loot without robbing adjacent houses using a bottom-up approach and recurrence relation.