```
public class Solution
extends Object
```
140 - Word Break II\. Hard Given a string `s` and a dictionary of strings `wordDict`, add spaces in `s` to construct a sentence where each word is a valid dictionary word. Return all such possible sentences in **any order**. **Note** that the same word in the dictionary may be reused multiple times in the segmentation. **Example 1:** **Input:** s = "catsanddog", wordDict = ["cat","cats","and","sand","dog"] **Output:** ["cats and dog","cat sand dog"] **Example 2:** **Input:** s = "pineapplepenapple", wordDict = ["apple","pen","applepen","pine","pineapple"] **Output:** ["pine apple pen apple","pineapple pen apple","pine applepen apple"] **Explanation:** Note that you are allowed to reuse a dictionary word. **Example 3:** **Input:** s = "catsandog", wordDict = ["cats","dog","sand","and","cat"] **Output:** [] **Constraints:** * `1 <= s.length <= 20` * `1 <= wordDict.length <= 1000` * `1 <= wordDict[i].length <= 10` * `s` and `wordDict[i]` consist of only lowercase English letters. * All the strings of `wordDict` are **unique**.

public List<String> wordBreak(String s,
                              List<String> wordDict)

Class Solution