Java Clean Solution
Complexity\n- Time complexity:O(n)\n Add your time complexity here, e.g. O(n) \n\n- Space complexity:O(n)\n Add your space complexity here, e.g. O(n) \n\n# Code
# Complexity\n- Time complexity:$$O(n)$$\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:$$O(n)$$\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```java []\nclass Solution {\n    public String[] uncommonFromSentences(String s1, String s2) {\n        String [] str1 = s1.split(" ");\n        String [] str2 = s2.split(" ");\n\n        HashMap<String, Integer> map = new HashMap<>();\n        for(String s : str1){\n            map.put(s, map.getOrDefault(s,0)+1);\n        }\n\n        for(String s : str2){\n            map.put(s, map.getOrDefault(s,0)+1);\n        }\n\n        List<String> list = new ArrayList<>();\n        for(String i : map.keySet()){\n            if(map.get(i)==1) list.add(i);\n            \n        }\n        String [] arr = new String[list.size()];\n        for(int i=0; i<list.size(); i++){\n            arr[i] = list.get(i);\n        }\n        return arr;\n    }\n}\n```
['Hash Table', 'String', 'Counting', 'Java']