Leetcode Unique Word Abbreviation
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) 1 b) d|o|g --> d1g 1 1 1 1---5----0----5--8 c) i|nternationalizatio|n --> i18n 1 1---5----0 d) 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 no other word from the dictionary has the same abbreviation.
Example:
Given dictionary = [ "deer", "door", "cake", "card" ] isUnique("dear") ->false
isUnique("cart") ->true
isUnique("cane") ->false
isUnique("make") ->true
解题思路:
解题关键点有3个:
1. 找出word abbreviation 的规律,<first letter><number><last letter>,number = string.length() - 2
2. 当发现dictionary 里有相同的abbreviation, key 对应的value 变为""
3. The abbreviation of "hello", i.e., h3o already exists in the dictionary.
Input: ["hello"],isUnique("hello") Output: [false] Expected: [true]
If the given word itself is in the dictionary, and it has the unique abbreviation, then we should return true.
Java code:
public class ValidWordAbbr { private Map<String, String> map = new HashMap<String, String>(); public ValidWordAbbr(String[] dictionary) { for(int i = 0; i < dictionary.length; i++){ String key = abbreviate(dictionary[i]); if(!map.containsKey(key)){ map.put(key, dictionary[i]); }else{ map.put(key, ""); } } } private String abbreviate(String str){ return str.charAt(0) + Integer.toString(str.length() - 2)+ str.charAt(str.length()-1); } public boolean isUnique(String word) { String x = abbreviate(word); if(map.containsKey(x)){ if(map.get(x).equals(word)){ return true; }else { return false; } } return true; } } // Your ValidWordAbbr object will be instantiated and called as such: // ValidWordAbbr vwa = new ValidWordAbbr(dictionary); // vwa.isUnique("Word"); // vwa.isUnique("anotherWord");
Reference:
1. https://leetcode.com/discuss/62842/a-simple-java-solution-using-map-string-string
2. https://leetcode.com/discuss/62824/wrong-test-case