<p>Given a string <code>s</code> and a dictionary of strings <code>wordDict</code>, add spaces in <code>s</code> to construct a sentence where each word is a valid dictionary word. Return all such possible sentences in <strong>any order</strong>.</p> <p><strong>Note</strong> that the same word in the dictionary may be reused multiple times in the segmentation.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> s = "catsanddog", wordDict = ["cat","cats","and","sand","dog"] <strong>Output:</strong> ["cats and dog","cat sand dog"] </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> s = "pineapplepenapple", wordDict = ["apple","pen","applepen","pine","pineapple"] <strong>Output:</strong> ["pine apple pen apple","pineapple pen apple","pine applepen apple"] <strong>Explanation:</strong> Note that you are allowed to reuse a dictionary word. </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> s = "catsandog", wordDict = ["cats","dog","sand","and","cat"] <strong>Output:</strong> [] </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= s.length <= 20</code></li> <li><code>1 <= wordDict.length <= 1000</code></li> <li><code>1 <= wordDict[i].length <= 10</code></li> <li><code>s</code> and <code>wordDict[i]</code> consist of only lowercase English letters.</li> <li>All the strings of <code>wordDict</code> are <strong>unique</strong>.</li> </ul>