Given a list of strings words representing an English Dictionary, find the longest word in words that can be built one character at a time by other words in words. If there is more than one possible answer, return the longest word with the smallest lexicographical order.
Example 1:
Input: words = ["w","wo","wor","worl", "world"] Output: "world" Explanation: The word "world" can be built one character at a time by "w", "wo", "wor", and "worl".
Example 2:
Input: words = ["a", "banana", "app", "appl", "ap", "apply", "apple"] Output: "apple" Explanation: Both "apply" and "apple" can be built from other words in the dictionary. However, "apple" is lexicographically smaller than "apply".
Note:
words will be in the range [1, 1000].words[i] will be in the range [1, 30].
/*** @param {string[]} words* @return {string}*/var longestWord = function (words) {let res = "";words = words.sort();let set = new Set();for (let i in words) {let s = words[i];if (s.length == 1 || set.has(s.substring(0, s.length - 1))) {res = s.length > res.length ? s : res;set.add(s);}}return res;};
720. Longest Word in Dictionary 字典中最长的单词
原文：http://www.cnblogs.com/xiejunzhao/p/7846743.html