<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 {
public:
    int numEnclaves(vector<vector<int>>& grid) {
        queue<pair<int,int>> q;
        map<pair<int,int>,int> mp;
        int c=0;
        for(int i=0;i<grid.size();i++){
            for(int j=0;j<grid[0].size();j++){
                if(grid[i][j]== 1) { c++;
                if(i==0 ||i== grid.size()-1 ||  j==0 || j==grid[0].size()-1 ){ q.push({i,j}); mp[{i,j}]++; }
                
                }
            }
        }
        int dir[4][2]= {{1,0},{-1,0},{0,1},{0,-1}};
        int d=0;
        while(!q.empty()){
            d++;
            int r= q.front().first;
            int c= q.front().second;
           // mp[{r,c}]++;
            for(int l= 0;l<4;l++){
                int i= r+dir[l][0];
                int j= c+dir[l][1];
                if(i<grid.size() && i>=0 && j<grid[0].size() && j>=0 && mp[{i,j}]== 0 && grid[i][j]==1){
                        q.push({i,j});
                        mp[{i,j}]++;
                }
           
            }
                 q.pop();
        }
     //   cout<<mp.size();
        //cout<<d<<c;
        return c-d;
    }
};
37887