Maximum Product of Word Lengths

一道位操作的好题。

当中的两个操作很好。

public class Solution {
    public int maxProduct(String[] words) {
        if (words == null || words.length == 0) {
            return 0;
        }
        int[] elements = new int[words.length];
        for (int i = 0; i < words.length; i++) {
            String word = words[i];
            for (int j = 0; j < word.length(); j++) {
                elements[i] = elements[i] | (1<<(word.charAt(j) - 'a'));
            }
        }
        int max = 0;
        for (int i = 0; i < words.length; i++) {
            for (int j = i + 1; j < words.length; j++) {
                if ((elements[i] & elements[j]) == 0) {
                    max = Math.max(max, words[i].length()*words[j].length());
                }
            }
        }
        return max;
    }
}