Search Suggestions System

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"]]

Example 3:

Input: products = ["bags","baggage","banner","box","cloths"], searchWord = "bags"
Output: [["baggage","bags","banner"],["baggage","bags","banner"],["baggage","bags"],["bags"]]

 

Constraints:

  • 1 <= products.length <= 1000
  • 1 <= products[i].length <= 3000
  • 1 <= sum(products[i].length) <= 2 * 104
  • All the strings of products are unique.
  • products[i] consists of lowercase English letters.
  • 1 <= searchWord.length <= 1000
  • searchWord consists of lowercase English letters.
SOLUTION:
class Node:
    def __init__(self, val, children, words):
        self.val = val
        self.children = children
        self.words = words

class Trie:
    def __init__(self):
        self.root = Node(None, {}, set())

    def insert(self, word, pos) -> None:
        n = len(word)
        curr = self.root
        for i, c in enumerate(word):
            if c in curr.children:
                curr = curr.children[c]
            else:
                newcurr = Node(c, {}, set())
                curr.children[c] = newcurr
                curr = newcurr
            curr.words.add(pos)
        
    def startsWith(self, prefix, res):
        n = len(prefix)
        curr = self.root
        for i, c in enumerate(prefix):
            if c in curr.children:
                curr = curr.children[c]
                res.append(curr.words)
            else:
                return set()
        return curr.words

class Solution:
    def suggestedProducts(self, products: List[str], searchWord: str) -> List[List[str]]:
        n = len(searchWord)
        trie = Trie()
        for i, product in enumerate(products):
            trie.insert(product, i)
        res = []
        trie.startsWith(searchWord, res)
        while len(res) < n:
            res.append({})
        return [sorted([products[i] for i in curr])[:3] for curr in res]

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