NumberOfEnclaves.cpp

// User function Template for C++

class Solution {
  public:
    int numberOfEnclaves(vector<vector<int>> &grid) {
        // Code here
         int n=grid.size(),m=grid[0].size();
        vector<vector<int>>visited(n,vector<int>(m,0));
        queue<pair<int,int>>q;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                // first row,first column,last row,last column
                if(i==0 || j==0 || i==n-1 || j==m-1){
                    if(grid[i][j]==1){
                        q.push({i,j});
                        visited[i][j]=1;
                    }
                }
            }
        }
        int delrow[]={-1,0,+1,0};
        int delcol[]={0,+1,0,-1};
        while(!q.empty()){
            int row=q.front().first;
            int col=q.front().second;
            q.pop();
            for(int i=0;i<4;i++){
                int nrow=row+delrow[i];
                int ncol=col+delcol[i];
                if(nrow>=0 && nrow<n && ncol>=0 && ncol<m && visited[nrow][ncol]==0
                && grid[nrow][ncol]==1){
                    q.push({nrow,ncol});
                    visited[nrow][ncol]=1;
                }
            }
        }
        int cnt=0;
        for(int i=0;i<n;i++){
            for(int j=0;j<m;j++){
                if(grid[i][j]==1 && visited[i][j]==0){
                    cnt++;
                }
            }
        }
        return cnt;
    }
};