From ef3ab46d9f1e14fbffc6558edf1a4cc9eb4af8bb Mon Sep 17 00:00:00 2001
From: priyamdas009 <priyamdas009@gmail.com>
Date: Mon, 11 Oct 2021 13:19:55 +0530
Subject: [PATCH] Added cpp solution for Surrounding Regions

---
 leetCode/Surrounded Regions.cpp | 37 +++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 leetCode/Surrounded Regions.cpp

diff --git a/leetCode/Surrounded Regions.cpp b/leetCode/Surrounded Regions.cpp
new file mode 100644
index 0000000..120db54
--- /dev/null
+++ b/leetCode/Surrounded Regions.cpp	
@@ -0,0 +1,37 @@
+class Solution {
+public:
+    void solve(vector<vector<char>>& board) {
+        for(int i=0; i<board.size(); i++) {
+            for(int j=0; j<board[0].size(); j++) {
+                if(i==0 || j==0 || i==board.size()-1 || j==board[0].size()-1) {
+                    if(board[i][j] == 'O') {
+                        dfs(board, i, j);
+                    }
+                }
+            }
+        }
+        for(int i=0; i<board.size(); i++) {
+            for(int j=0; j<board[0].size(); j++) {
+                if(board[i][j] == 'O')  board[i][j] = 'X';
+                if(board[i][j] == 'V')  board[i][j] = 'O';
+            }
+        }
+    }
+
+    void dfs(vector<vector<char>>& board, int i, int j) {
+        if(i>=0 && j>=0 && i<board.size() && j<board[0].size() && board[i][j]!='X' && board[i][j]!='V') {
+            board[i][j] = 'V';
+            dfs(board, i, j-1);
+            dfs(board, i, j+1);
+            dfs(board, i-1, j);
+            dfs(board, i+1, j);
+        }
+    }
+
+    bool isNotValid(int i, int j, int row, int col) {
+        if(i-1<0 || i+1>=row || j-1<0 || j+1>=col) {
+            return true;
+        }
+        return false;
+    }
+};