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:
Given ["abcw", "baz", "foo", "bar", "xtfn", "abcdef"]
Return 16
The two words can be "abcw", "xtfn".
Example 2:
Given ["a", "ab", "abc", "d", "cd", "bcd", "abcd"]
Return 4
The two words can be "ab", "cd".
Example 3:
Given ["a", "aa", "aaa", "aaaa"]
Return 0
No such pair of words.
public static int maxProduct(String[] words){ int[] arri = new int[words.length]; for (int i = 0; i < words.length; i++) { for (int j = 0; j < words[i].length(); j++) { arri[i] |= 1<<(words[i].charAt(j)-'a'); } } int ans = 0; for (int i = 0; i < words.length-1; i++) { for (int j = i+1; j < words.length; j++) { if ((arri[i] & arri[j]) == 0) {// 没有重复的字母 ans = Math.max(ans, words[i].length()*words[j].length()); } } } return ans; }
移位运算符：