You are given an array of strings products and a string searchWord.
Design a system that suggests at most three product names from products after each character of searchWord is typed. Suggested products should have common prefix with searchWord. If there are more than three products with a common prefix return the three lexicographically minimums products.
Return a list of lists of the suggested products after each character of searchWord is typed.
Example 1:
Input: products = ["mobile","mouse","moneypot","monitor","mousepad"], searchWord = "mouse" Output: [["mobile","moneypot","monitor"],["mobile","moneypot","monitor"],["mouse","mousepad"],["mouse","mousepad"],["mouse","mousepad"]] Explanation: products sorted lexicographically = ["mobile","moneypot","monitor","mouse","mousepad"]. After typing m and mo all products match and we show user ["mobile","moneypot","monitor"]. After typing mou, mous and mouse the system suggests ["mouse","mousepad"].
Example 2:
Input: products = ["havana"], searchWord = "havana" Output: [["havana"],["havana"],["havana"],["havana"],["havana"],["havana"]] Explanation: The only word "havana" will be always suggested while typing the search word.
Constraints:
1 <= products.length <= 10001 <= products[i].length <= 30001 <= sum(products[i].length) <= 2 * 104products are unique.products[i] consists of lowercase English letters.1 <= searchWord.length <= 1000searchWord consists of lowercase English letters.This approach involves sorting the products array first and then iteratively constructing prefixes from the searchWord. For each prefix, use a simple linear search over the sorted products array to find matches. By keeping the products sorted, it ensures that we can easily pick the smallest lexicographical options.
After sorting, for every prefix of the searchWord, we traverse the sorted products list, check if the product starts with the current prefix, and collect up to three matches.
This Python code starts by sorting the list of products. As we iterate through each character of the searchWord, it builds the prefix and filters products that start with the current prefix. We then select the first three such products.
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Time Complexity: O(n log n) due to sorting, where n is the length of products. Each prefix search is O(n), leading to an overall complexity of O(n log n + m * n), where m is the length of searchWord.
Space Complexity: O(1) additional space is needed outside the result storage, although storing results may take O(m * 3) space.
This approach aims at using a Trie to efficiently handle prefix matching. With a Trie, we insert all product names into the Trie. As each character is typed in the searchWord, we traverse the Trie to check for the top three lexicographical matches.
Using a Trie allows us to handle the prefix matching efficiently by navigating through the structure step by step according to the current prefix.
This Python code uses a Trie structure. We create nodes for each character and keep track of the top three suggestions within the TrieNode. As searchWord is typed, we navigate the Trie and retrieve suggestions.
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Time Complexity: O(n m) to insert all products (where n is number of products and m is max product length), and O(k) to search for each prefix (where k is the length of searchWord).
Space Complexity: O(n m) for the Trie storage, since we store each character of every word.
| Approach | Complexity |
|---|---|
| Sorting and Linear Search Approach | Time Complexity: O(n log n) due to sorting, where n is the length of products. Each prefix search is O(n), leading to an overall complexity of O(n log n + m * n), where m is the length of searchWord. Space Complexity: O(1) additional space is needed outside the result storage, although storing results may take O(m * 3) space. |
| Trie Data Structure Approach | Time Complexity: O(n m) to insert all products (where n is number of products and m is max product length), and O(k) to search for each prefix (where k is the length of searchWord). Space Complexity: O(n m) for the Trie storage, since we store each character of every word. |
Search Suggestions System - Leetcode 1268 - Python • NeetCode • 50,737 views views
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