5 articles
LeetCode 1032 — design a class that returns true whenever the suffix of a streamed character sequence matches any dictionary word. Solved with a reverse trie and a bounded sliding buffer in O(W) per query.
LeetCode 745 — design a structure that returns the highest-indexed word matching a given prefix and suffix. The combined-key trie inserts every (suffix#word) variant, turning a 2D query into a 1D trie walk.
LeetCode 820 — encode a list of words into the shortest reference string where each word appears as a suffix terminated by #. Build a trie of reversed words; only words at trie leaves contribute their length plus one to the answer.
Map of every important trie variant you need for FAANG interviews — binary trie for XOR, reverse trie for suffix matching, counted trie for prefix scoring, offline trie for bounded queries, and the design patterns that compose them.
Count the number of distinct substrings of a string. The elegant trick: every substring is a prefix of some suffix, so a suffix trie has exactly one node per distinct non-empty substring. Count nodes during insertion in O(N^2).