My strategy for designing an auto-complete system involves utilizing the Trie data structure, which is a tree-like format that allows for efficient key retrieval within a dataset of strings. Step 1: Data Structure - The primary data structure will be a Trie. Each node consists of a character, a frequency count, and a hash map. The character represents the letter at the current node, while the frequency count is used to sort the results later. The hash map directs to subsequent characters that form potential word suggestions. Step 2: Constructing the Trie - Begin by initializing the root of the Trie. For each word in the dictionary, start at the root and navigate to the corresponding character node. If a node does not exist, create a new one. Update the frequency counter with each traversal. Step 3: Searching the Trie for Auto-Completion : When a user inputs a prefix, we start searching from the root of the Trie and proceed according to each character of the prefix. If the entire prefix is located, we implement a Depth-First Search (DFS) approach to retrieve all relevant completions until we identify a sufficient number of the most frequently occurring words. Step 4: Ranking Suggestions : We assign ranks to each word based on their frequency counts and return those that are most commonly used. Step 5: Managing Edge Cases : If the entered prefix is not found, no completion suggestions will be provided. Alternatively, we could offer correction suggestions in such cases, similar to a spell-checker.