211. Design Add and Search Words Data Structure
Medium
Design a data structure that supports adding new words and finding if a string matches any previously added string.
Implement the
WordDictionary class:WordDictionary()Initializes the object.void addWord(word)Addswordto the data structure, it can be matched later.bool search(word)Returnstrueif there is any string in the data structure that matcheswordorfalseotherwise.wordmay contain dots'.'where dots can be matched with any letter.
Example:
Input
["WordDictionary","addWord","addWord","addWord","search","search","search","search"]
[[],["bad"],["dad"],["mad"],["pad"],["bad"],[".ad"],["b.."]]
Output
[null,null,null,null,false,true,true,true]
Explanation
WordDictionary wordDictionary = new WordDictionary();
wordDictionary.addWord("bad");
wordDictionary.addWord("dad");
wordDictionary.addWord("mad");
wordDictionary.search("pad"); // return False
wordDictionary.search("bad"); // return True
wordDictionary.search(".ad"); // return True
wordDictionary.search("b.."); // return True
Constraints:
1 <= word.length <= 25wordinaddWordconsists of lowercase English letters.wordinsearchconsist of'.'or lowercase English letters.- There will be at most
3dots inwordforsearchqueries. - At most
104calls will be made toaddWordandsearch.
Trie
type WordDictionary struct {
Children [26]*WordDictionary
isTerminal bool
}
func Constructor() WordDictionary {
return WordDictionary{}
}
func (this *WordDictionary) AddWord(word string) {
for i:=0; i<len(word); i++ {
if this.Children[word[i] - 'a'] == nil {
this.Children[word[i] - 'a'] = &WordDictionary{}
}
this = this.Children[word[i] - 'a']
}
this.isTerminal = true
}
func (this *WordDictionary) Search(word string) bool {
for i:=0; i<len(word); i++ {
if word[i] == '.' {
for j:=0; j<26; j++ {
if this.Children[j] != nil && this.Children[j].Search(word[i+1:]) {
return true
}
}
return false
}
if this.Children[word[i] - 'a'] == nil {
return false
}
this = this.Children[word[i] - 'a']
}
if this.isTerminal == true {
return true
}
return false
}
/**
* Your WordDictionary object will be instantiated and called as such:
* obj := Constructor();
* obj.AddWord(word);
* param_2 := obj.Search(word);
*/
Last modified 6mo ago