/**

* Difficulty:

* Medium

*

* Desc:

* Given a non-empty string s and a dictionary wordDict containing a list of non-empty words,

* determine if s can be segmented into a space-separated sequence of one or more dictionary words.

* You may assume the dictionary does not contain duplicate words.

*

* Example:

* Given

* s = "leetcode",

* dict = ["leet", "code"].

* Return true because "leetcode" can be segmented as "leet code".

*

* 判断一个单词是否可以利用给定数组中的各元素进行截断。数组内元素没有重复，但可以重复使用

*/

/**

* @param {string} s

* @param {string[]} wordDict

* @return {boolean}

*/

var wordBreak = function(s, wordDict) {

const set = new Set(wordDict);

const tmp = {};

const check = (index) => {

if (tmp[index] !== undefined) return tmp[index];

if (index >= s.length) return true;

for (let i = index; i < s.length; i += 1) {

if (set.has(s.slice(index, i + 1))) {

tmp[i + 1] = check(i + 1);

if (tmp[i + 1]) {

return true;

}

}

}

return false;

};

return check(0);

};