Given two string arrays??and?, return?the number of strings that appear?exactly once?in?each?of the two arrays.

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Example 1:

Input: words1 = ["leetcode","is","amazing","as","is"], words2 = ["amazing","leetcode","is"]Output: 2Explanation:- "leetcode" appears exactly once in each of the two arrays. We count this string. - "amazing" appears exactly once in each of the two arrays. We count this string. - "is" appears in each of the two arrays, but there are 2 occurrences of it in Words1. We do not count this string. - "as" appears once in Words1, but does not appear in Words2. We do not count this string. Thus, there are 2 strings that appear exactly once in each of the two arrays.

Example 2:

Input: words1 = ["b","bb","bbb"], words2 = ["a","aa","aaa"]Output: 0Explanation: There are no strings that appear in each of the two arrays.

Example 3:

Input: words1 = ["a","ab"], words2 = ["a","a","a","ab"]Output: 1Explanation: The only string that appears exactly once in each of the two arrays is "ab".

Runtime:?4 ms, faster than?91.08%?of?Java?online submissions for?Count Common Words With One Occurrence.

Memory Usage:?42.3 MB, less than?49.22%?of?Java?online submissions for?Count Common Words With One Occurrence.