LeetCode 题解(256) : Unique Word Abbreviation

题目：

An abbreviation of a word follows the form <first letter><number><last letter>. Below are some examples of word abbreviations:

a) it                      --> it    (no abbreviation)     1b) d|o|g                   --> d1g              1    1  1     1---5----0----5--8c) i|nternationalizatio|n  --> i18n              1     1---5----0d) l|ocalizatio|n          --> l10n

Assume you have a dictionary and given a word, find whether its abbreviation is unique in the dictionary. A word's abbreviation is unique if noother word from the dictionary has the same abbreviation.

Example:

Given dictionary = [ "deer", "door", "cake", "card" ]isUnique("dear") -> falseisUnique("cart") -> trueisUnique("cane") -> falseisUnique("make") -> true

题解：

HashMap。

C++版：

class ValidWordAbbr {public:    ValidWordAbbr(vector<string> &dictionary) {        for(auto i : dictionary) {            string key = i[0] + to_string(i.length() - 2) + i[i.length() - 1];            if(d.find(key) == d.end()) {                vector<string> list;                list.push_back(i);                d.insert(pair<string, vector<string>>(key, list));            } else {                d[key].push_back(i);            }        }    }    bool isUnique(string word) {        string key = word[0] + to_string(word.length() - 2) + word[word.length() - 1];        if(d.find(key) == d.end())            return true;        else if(d[key].size() == 1 && d[key][0] == word)            return true;        return false;    }    private:    unordered_map<string, vector<string>> d;};// Your ValidWordAbbr object will be instantiated and called as such:// ValidWordAbbr vwa(dictionary);// vwa.isUnique("hello");// vwa.isUnique("anotherWord");

Java版：

public class ValidWordAbbr {    public ValidWordAbbr(String[] dictionary) {        for(String s: dictionary) {            String key = s.charAt(0) + Integer.toString(s.length() - 2) + s.charAt(s.length() - 1);            if(d.containsKey(key)) {                d.get(key).add(s);            } else {                List<String> l = new ArrayList<>();                l.add(s);                d.put(key, l);            }        }    }    public boolean isUnique(String word) {        String key = word.charAt(0) + Integer.toString(word.length() - 2) + word.charAt(word.length() - 1);        if(!d.containsKey(key))            return true;        else if(d.get(key).size() < 2  && d.get(key).get(0).equals(word))            return true;        return false;    }        private HashMap<String, List<String>> d = new HashMap<>();}// Your ValidWordAbbr object will be instantiated and called as such:// ValidWordAbbr vwa = new ValidWordAbbr(dictionary);// vwa.isUnique("Word");// vwa.isUnique("anotherWord");

Python版：

class ValidWordAbbr(object):    def __init__(self, dictionary):        """        initialize your data structure here.        :type dictionary: List[str]        """        self.d = collections.defaultdict(list)        for i in dictionary:            self.d[i[0] + str(len(i) - 2) + i[-1]].append(i)    def isUnique(self, word):        """        check if a word is unique.        :type word: str        :rtype: bool        """        key = word[0] + str(len(word) - 2) + word[-1]        if key not in self.d:            return True        elif len(self.d[key]) == 1 and self.d[key][0] == word:            return True        else:            return False# Your ValidWordAbbr object will be instantiated and called as such:# vwa = ValidWordAbbr(dictionary)# vwa.isUnique("word")# vwa.isUnique("anotherWord")