LeetCode 1048 Longest String Chain - Problem Statement

Solve Longest String Chain from LeetCode. Word A is a predecessor of word B if you can insert exactly one letter into A to get B. Find the longest chain of words where each word is a predecessor of the next.

Hint: Sort words by length. Use a HashMap where $dp[word]$ = longest chain ending at that word. For each word, check all possible predecessors (remove one char).