Given a list of products and a searchWord being typed one character at a time, return a list of suggestion lists — one per character typed — where each entry holds up to 3 lexicographically smallest products that still have the typed-so-far prefix. Sorting the products once turns "find every product with this prefix" into a contiguous block that a binary search can locate directly. Going further, inserting the sorted products into a trie — and letting each node cache the first 3 products that ever pass through it — turns every later query into a plain O(1)-per-character walk with no searching left to do at all: the trie already did the sorting and filtering work once, up front.