Create 1020.cpp

Author: JanaSabuj

1020/1020.cpp

@@ -0,0 +1,45 @@
+class Solution {
+public:
+     int dx[4] = {0, 0, 1, -1};
+    int dy[4] = {1, -1, 0, 0}; 
+    
+    bool valid(int r, int c, int n, int m){
+        return (r >= 0 and r < n and c >= 0 and c < m);
+    }
+    
+    void dfs(vector<vector<int>>& board, int x, int y, int n, int m){
+        board[x][y] = 2;
+        for(int i = 0; i < 4; i++){
+            int r = x + dx[i];
+            int c = y + dy[i];
+            
+            if(valid(r,c,n,m) and board[r][c] == 1)
+                dfs(board, r, c, n, m);                
+        }        
+    }  
+    int numEnclaves(vector<vector<int>>& board) {
+        int n = board.size();
+        if(n == 0)
+            return 0;
+        int m = board[0].size();
+        
+        for(int i = 0; i < n; i++){
+            for(int j = 0; j < m; j++){
+                if(board[i][j] == 1)
+                    if(i == 0 or i == n-1 or j == 0 or j == m-1){
+                        dfs(board, i, j, n, m);
+                    }
+            }
+        }
+        
+        int cnt = 0;
+        for(int i = 0; i < n; i++){
+            for(int j = 0; j < m; j++){
+                if(board[i][j] == 1)                    
+                    cnt++;
+            }     
+        }
+        
+        return cnt;
+    }
+};