[leetcode] 1020. Number of Enclaves : https://leetcode.com/problems/number-of-enclaves/

Number of Enclaves.cpp

class Solution {
private:
    int dx[4] = {-1, 1, 0, 0};
    int dy[4] = {0, 0, -1, 1};    
    
public:
    
    int getAnswer(int x, int y, vector<vector<int>>& A){
        int r = A.size();
        int c = A[0].size();
        
        bool isAns = true;
        queue<pair<int,int>> q;
        q.push({x, y});
        A[x][y] = 0;
        int cnt = 0;
        
        while(!q.empty()){
            int x = q.front().first;
            int y = q.front().second;
            q.pop();
            cnt++;
            
            for(int i=0;i<4;i++){
                int nx = x + dx[i];
                int ny = y + dy[i];
                if(nx < 0 || r <= nx || ny < 0 || c <= ny){
                    isAns = false;
                    continue;
                }
                if(A[nx][ny] == 0) continue;
                q.push({nx,ny});
                A[nx][ny] = 0;
            }
        }
        return isAns ? cnt : 0;
    }
    
    int numEnclaves(vector<vector<int>>& A) {
        int answer = 0;
        for(int i=0;i<A.size();i++){
            for(int j=0;j<A[i].size();j++){
                if(A[i][j] == 1)
                    answer += getAnswer(i,j,A);
            }
        }
        return answer;
    }
};