2 Java solutions. one using a hashmap, the other using a hashset for Design Add and Search Words Data Structure.
Instructions: 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) Adds word to the data structure, it can be matched later. bool search(word) Returns true if there is any string in the data structure that matches word or false otherwise. word may 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 <= 500 word in addWord consists lower-case English letters. word in search consist of '.' or lower-case English letters. At most 50000 calls will be made to addWord and search.
Link to question: https://leetcode.com/problems/design-add-and-search-words-data-structure/