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.
Test Cases
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 = ["havana"], searchWord = "tatiana"
Output: [[],[],[],[],[],[],[]]
Example 4:
Input: products = ["bags","baggage","banner","box","cloths"], searchWord = "bags"
Output: [["baggage","bags","banner"],["baggage","bags","banner"],["baggage","bags"],["bags"]]
Solution
class Solution {
public List<List<String>> suggestedProducts(String[] products, String searchWord) {
TrieNode root = new TrieNode();
for(String product: products) {
root.add(product);
}
int n = searchWord.length();
List<List<String>> res = new ArrayList<>();
for(int i=0; i<n; i++) {
char c = searchWord.charAt(i);
int pos = c - 'a';
List<String> list = new ArrayList<>();
if (root != null && root.children[pos] != null) {
PriorityQueue<String> pq = root.children[pos].top;
while(!pq.isEmpty()) list.add(0, pq.poll());
pq.addAll(list);
}
res.add(list);
if (root == null) continue;
root = root.children[pos];
}
return res;
}
}
class TrieNode {
PriorityQueue<String> top;
TrieNode[] children;
boolean isEndWord;
static int MAX_SIZE = 3;
TrieNode() {
top = new PriorityQueue<>((a,b) -> b.compareTo(a));
children = new TrieNode[26];
isEndWord = false;
}
public void add(String s) {
TrieNode root = this;
int n = s.length();
for(int i=0; i<n; i++) {
char c = s.charAt(i);
int pos = c - 'a';
if (root.children[pos] == null) {
root.children[pos] = new TrieNode();
}
PriorityQueue<String> pq = root.children[pos].top;
if (pq.size() < MAX_SIZE) pq.offer(s);
else {
if (pq.peek().compareTo(s) > 0) {
pq.poll();
pq.offer(s);
}
}
root.children[pos].top = pq;
root = root.children[pos];
}
root.isEndWord = true;
}
}