Edit Distance
Find minimum operations to convert one string to another
Longest Common Subsequence
Find the length of the longest common subsequence between two strings
Regular Expression Matching
Implement regular expression matching with '.' and '*'
Word Break II (LC 140) — DFS + Memo DP (Hard)
Solve LeetCode 140 Word Break II with DFS + memoization DP. Output-sensitive (≈O(n²)+answers). Step-by-step for interviews—practice now.