Given a string array words, find the maximum value of length(word[i]) * length(word[j]) where the two words do not share common letters. You may assume that each word will contain only lower case letters. If no such two words exist, return 0.
Example 1:
Input:["abcw","baz","foo","bar","xtfn","abcdef"]Output:16 Explanation:The two words can be"abcw", "xtfn".
Example 2:
Input:["a","ab","abc","d","cd","bcd","abcd"]Output:4 Explanation:The two words can be"ab", "cd".
Example 3:
Input:["a","aa","aaa","aaaa"]Output:0 Explanation:No such pair of words.