https://leetcode.com/problems/uncommon-words-from-two-sentences/
We are given two sentences
A and B. (A sentence is a string of space separated words. Each word consists only of lowercase letters.)
A word is uncommon if it appears exactly once in one of the sentences, and does not appear in the other sentence.
Return a list of all uncommon words.
You may return the list in any order.
Example 1:
Input: A = "this apple is sweet", B = "this apple is sour" Output: ["sweet","sour"]
Example 2:
Input: A = "apple apple", B = "banana" Output: ["banana"]
Every uncommon word occurs exactly once in total. We can count the number of occurrences of every word, then return ones that occur exactly once.
public String[] uncommonFromSentences(String A, String B) {
Map<String, Integer> count = new HashMap();
for (String word : A.split(" "))
count.put(word, count.getOrDefault(word, 0) + 1);
for (String word : B.split(" "))
count.put(word, count.getOrDefault(word, 0) + 1);
List<String> ans = new LinkedList();
for (String word : count.keySet())
if (count.get(word) == 1)
ans.add(word);
return ans.toArray(new String[ans.size()]);
}
