<p>You are given an <code>m x n</code> binary matrix <code>grid</code>, where <code>0</code> represents a sea cell and <code>1</code> represents a land cell.</p>

<p>A <strong>move</strong> consists of walking from one land cell to another adjacent (<strong>4-directionally</strong>) land cell or walking off the boundary of the <code>grid</code>.</p>

<p>Return <em>the number of land cells in</em> <code>grid</code> <em>for which we cannot walk off the boundary of the grid in any number of <strong>moves</strong></em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/18/enclaves1.jpg" style="width: 333px; height: 333px;" />
<pre>
<strong>Input:</strong> grid = [[0,0,0,0],[1,0,1,0],[0,1,1,0],[0,0,0,0]]
<strong>Output:</strong> 3
<strong>Explanation:</strong> There are three 1s that are enclosed by 0s, and one 1 that is not enclosed because its on the boundary.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/18/enclaves2.jpg" style="width: 333px; height: 333px;" />
<pre>
<strong>Input:</strong> grid = [[0,1,1,0],[0,0,1,0],[0,0,1,0],[0,0,0,0]]
<strong>Output:</strong> 0
<strong>Explanation:</strong> All 1s are either on the boundary or can reach the boundary.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>m == grid.length</code></li>
	<li><code>n == grid[i].length</code></li>
	<li><code>1 &lt;= m, n &lt;= 500</code></li>
	<li><code>grid[i][j]</code> is either <code>0</code> or <code>1</code>.</li>
</ul>

class Solution:
    def numEnclaves(self, grid: List[List[int]]) -> int:
        rows = len(grid)
        cols = len(grid[0])

        # vis = [[0 for _ in range(rows)] for _ in range(cols)]
        q = deque()

        # Traverse the rows - first and last
        for i in [0, rows - 1]:
            for j in range(cols):
                if grid[i][j] == 1:
                    q.append((i, j))
                    grid[i][j] = 0
        
        # Traverse the cols - first and last
        for i in range(rows):
            for j in [0, cols - 1]:
                if grid[i][j] == 1:
                    q.append((i, j))
                    grid[i][j] = 0

        direc = [[-1, 0], [1, 0], [0, 1], [0, -1]]
        while q:
            r, c = q.popleft()

            for dr, dc in direc:
                i, j = r + dr, dc + c
                if i >= 0 and i < rows and j >= 0 and j < cols and grid[i][j] == 1:
                    q.append((i, j))
                    grid[i][j] = 0
        

        cnt = 0
        for i in range(rows):
            for j in range(cols):
                if grid[i][j] == 1: cnt += 1
        return cnt
18200