leetcode -- Maximum Product of Word Lengths -- 重点

https://leetcode.com/problems/maximum-product-of-word-lengths/

主要思路：http://www.jianshu.com/p/bb84b0f866c9

用26 bit 的int来convert a word to a bit number.

最终solution还是O(n2)的

code参考：http://bookshadow.com/weblog/2015/12/16/leetcode-maximum-product-word-lengths/

class Solution(object):    def maxProduct(self, words):        """        :type words: List[str]        :rtype: int        """        nums = []        size = len(words)        for w in words:            nums += sum(1 << (ord(x) - ord('a')) for x in set(w))#这里就是把a存到第一位，把z存到第26位        ans = 0        for x in range(size):            for y in range(size):                if not (nums[x] & nums[y]):                    ans = max(len(words[x]) * len(words[y]), ans)        return ans