qilingit
diff --git a/‎June-LeetCoding-Challenge/17-Surrounded-Regions/Surrounded-Regions.py
Copy file name to clipboard
+46Lines changed: 46 additions & 0 deletions b/‎June-LeetCoding-Challenge/17-Surrounded-Regions/Surrounded-Regions.py
Copy file name to clipboard
+46Lines changed: 46 additions & 0 deletions
@@ -0,0 +1,46 @@
+class Solution:
+    def solve(self, board: List[List[str]]) -> None:
+        """
+        Do not return anything, modify board in-place instead.
+        """
+        if board:
+            for i in range(len(board)):
+                if board[i][0]=='O':
+                    self.bfs(board,i,0)
+                if board[i][len(board[0])-1]=='O':
+                    self.bfs(board,i,len(board[0])-1)
+            for j in range(len(board[0])):
+                if board[0][j]=='O':
+                    self.bfs(board,0,j)
+                if board[len(board)-1][j]=='O':
+                    self.bfs(board,len(board)-1,j)  
+            for i in range(len(board)):
+                for j in range(len(board[0])):
+                    if board[i][j]=='O':
+                        board[i][j]='X'
+                    if board[i][j]=='2':
+                        board[i][j]='O'
+        
+    def bfs(self,board,i,j):
+        q = [[i,j]]
+        while q!=[]:
+            pos = q.pop(0)
+            a = pos[0]
+            b = pos[1]
+            board[a][b] = '2'
+            if 0<=a+1<len(board):
+                if board[a+1][b]=='O':
+                    board[a+1][b]='2'
+                    q.append([a+1,b])
+            if 0<=a-1<len(board):
+                if board[a-1][b]=='O':
+                    board[a-1][b]='2'
+                    q.append([a-1,b])
+            if 0<=b+1<len(board[0]):
+                if board[a][b+1]=='O':
+                    board[a][b+1] = '2'
+                    q.append([a,b+1])
+            if 0<=b-1<len(board[0]):
+                if board[a][b-1]=='O':
+                    board[a][b-1] = '2'
+                    q.append([a,b-1])