dsa2 min read
Word Search Problems — Trie + Backtracking Patterns
Word Search I and II solved with DFS backtracking. Word Search II uses a Trie to prune the search space from O(N·4^L) per word to O(N·4^L) total for all words.
Read →
All Posts
1276 articles
dsa2 min read
Encode and Decode Strings — Delimiter and Length-Prefix Schemes
Design an encode/decode scheme for a list of strings. Length-prefix encoding (4-byte header per string) is collision-proof unlike delimiter-based approaches.
Read →
dsa2 min read
Shortest Palindrome — KMP on Reversed String
Add minimum characters to the front of a string to make it a palindrome. KMP trick: concatenate s + '#' + rev(s), find the LPS value at the last position.
Read →
dsa1 min read
Count Distinct Substrings — Suffix Array + LCP
Count the number of distinct substrings using the suffix array and LCP array. Total substrings minus sum of LCP values gives distinct count in O(n log n).
Read →
dsa2 min read
String Compression and Run-Length Encoding
Implement run-length encoding, string compression in-place, and decode compressed strings. Tests two-pointer technique and string manipulation.
Read →
Page 233 of 256