题目如下：
Given a string s and a dictionary of words dict, add spaces in s to construct a sentence where each word is a valid dictionary word.

Return all such possible sentences.

For example, given
s = "catsanddog",
dict = ["cat", "cats", "and", "sand", "dog"].

A solution is ["cats and dog", "cat sand dog"].

思路：用数组构造一个hashmap，用数组模拟栈模型， 用栈模型实现dps（深度优先算法）。

核心代码：

function solve(start){
    var childMap=map[hash(start)];
    var childMapLength=childMap.length;
    for(var i=0;i<childMapLength;i++){
        stack.push(childMap[i]);
        if(childMap[i].finish===s.length){  //正确答案
            answer.push(stringify(stack))
        }else{
            solve(childMap[i].finish);     //递归
        }
        stack.pop();
    }
}
solve(0);

测试结果
dict:

s=“abcdefghijk”

result:

leetcode算法 - Word Break II js实现