Unique Word Abbreviation
Total Accepted: 6495 Total Submissions: 41761 Difficulty: Easy
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
思路
- 注意["hello"],isUnique("hello") 是返回的true, hello是unique的单词
- 所以使用hashmap的时候要注意一下,如果key只对应一个,就放入这个string,如果多个,自然是无效的,设置为null
- 然后对比isUnique的时候,判断,首先是不是无效的,然后判断key对应的string是不是一致的
public class ValidWordAbbr {
HashMap<String, String> map;
public ValidWordAbbr(String[] dictionary) {
map = new HashMap<String, String>();
for(String str:dictionary){
String key = getKey(str);
if(map.containsKey(key)){
if(!map.get(key).equals(str)){
map.put(key, "");
}
}
else{
map.put(key, str);
}
}
}
public boolean isUnique(String word) {
return !map.containsKey(getKey(word))||map.get(getKey(word)).equals(word);
}
String getKey(String str){
if(str.length()<=2) return str;
return str.charAt(0)+Integer.toString(str.length()-2)+str.charAt(str.length()-1);
}
}