<p>You are given an <code>m x n</code> matrix <code>board</code>, representing the<strong> current </strong>state of a crossword puzzle. The crossword contains lowercase English letters (from solved words), <code>' '</code> to represent any <strong>empty </strong>cells, and <code>'#'</code> to represent any <strong>blocked</strong> cells.</p> <p>A word can be placed<strong> horizontally</strong> (left to right <strong>or</strong> right to left) or <strong>vertically</strong> (top to bottom <strong>or</strong> bottom to top) in the board if:</p> <ul> <li>It does not occupy a cell containing the character <code>'#'</code>.</li> <li>The cell each letter is placed in must either be <code>' '</code> (empty) or <strong>match</strong> the letter already on the <code>board</code>.</li> <li>There must not be any empty cells <code>' '</code> or other lowercase letters <strong>directly left or right</strong><strong> </strong>of the word if the word was placed <strong>horizontally</strong>.</li> <li>There must not be any empty cells <code>' '</code> or other lowercase letters <strong>directly above or below</strong> the word if the word was placed <strong>vertically</strong>.</li> </ul> <p>Given a string <code>word</code>, return <code>true</code><em> if </em><code>word</code><em> can be placed in </em><code>board</code><em>, or </em><code>false</code><em> <strong>otherwise</strong></em>.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/10/04/crossword-ex1-1.png" style="width: 478px; height: 180px;" /> <pre> <strong>Input:</strong> board = [["#", " ", "#"], [" ", " ", "#"], ["#", "c", " "]], word = "abc" <strong>Output:</strong> true <strong>Explanation:</strong> The word "abc" can be placed as shown above (top to bottom). </pre> <p><strong class="example">Example 2:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/10/04/crossword-ex2-1.png" style="width: 180px; height: 180px;" /> <pre> <strong>Input:</strong> board = [[" ", "#", "a"], [" ", "#", "c"], [" ", "#", "a"]], word = "ac" <strong>Output:</strong> false <strong>Explanation:</strong> It is impossible to place the word because there will always be a space/letter above or below it.</pre> <p><strong class="example">Example 3:</strong></p> <img alt="" src="https://assets.leetcode.com/uploads/2021/10/04/crossword-ex3-1.png" style="width: 478px; height: 180px;" /> <pre> <strong>Input:</strong> board = [["#", " ", "#"], [" ", " ", "#"], ["#", " ", "c"]], word = "ca" <strong>Output:</strong> true <strong>Explanation:</strong> The word "ca" can be placed as shown above (right to left). </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == board.length</code></li> <li><code>n == board[i].length</code></li> <li><code>1 <= m * n <= 2 * 10<sup>5</sup></code></li> <li><code>board[i][j]</code> will be <code>' '</code>, <code>'#'</code>, or a lowercase English letter.</li> <li><code>1 <= word.length <= max(m, n)</code></li> <li><code>word</code> will contain only lowercase English letters.</li> </ul>