【Leetcode】140.单词拆分II（Hard）
一、题目
1、题目描述
给定一个字符串 s 和一个字符串字典 wordDict ，在字符串 s 中增加空格来构建一个句子，使得句子中所有的单词都在词典中。以任意顺序 返回所有这些可能的句子。
注意：词典中的同一个单词可能在分段中被重复使用多次。
示例1：
输入: s = "catsanddog", wordDict = ["cat","cats","and","sand","dog"]
输出: ["cats and dog","cat sand dog"]
示例2：
输入: s = "pineapplepenapple", wordDict = ["apple","pen","applepen","pine","pineapple"]
输出: ["pine apple pen apple","pineapple pen apple","pine applepen apple"]
解释: 注意你可以重复使用字典中的单词。
示例3：
输入:s = "catsandog", wordDict = ["cats","dog","sand","and","cat"]
输出:[]
提示