LC 676. Implement Magic Dictionary

Posted 2021-01-31 ethanhong

Implement a magic directory with buildDict, and search methods.

For the method buildDict, you‘ll be given a list of non-repetitive words to build a dictionary.

For the method search, you‘ll be given a word, and judge whether if you modify exactly one character into another character in this word, the modified word is in the dictionary you just built.

Example 1:

Input: buildDict(["hello", "leetcode"]), Output: Null
Input: search("hello"), Output: False
Input: search("hhllo"), Output: True
Input: search("hell"), Output: False
Input: search("leetcoded"), Output: False

 

Note:

1. You may assume that all the inputs are consist of lowercase letters a-z.
2. For contest purpose, the test data is rather small by now. You could think about highly efficient algorithm after the contest.
3. Please remember to RESET your class variables declared in class MagicDictionary, as static/class variables are persisted across multiple test cases. Please see here for more details.

 

 

Runtime: 0 ms, faster than 100.00% of C++ online submissions for Implement Magic Dictionary.

 

class MagicDictionary {
public:
  vector<string> strvec;
  explicit MagicDictionary() = default;

  void buildDict(const vector<string>& dict) {
    strvec = dict;
  }

  bool search(const string& word) {
    
    for(auto& vs : strvec){
      if(vs.size() != word.size()) continue;
      int idx = -1;
      bool fit = true;
      unordered_set<char> s;
      for(int i=0; i<word.size(); i++){
        s.insert(word[i]);
        if(idx == -1 && word[i] != vs[i]) {idx = i;}
        else if(idx != -1 && word[i] != vs[i]) {fit = false; break;}
      }
      if(idx != -1 && fit && s.count(word[idx])) return true;
    }
    return false;
  }
};