Create 463. Island Perimeter.py

Author: 724thomas

leetcode3/최원준/463. Island Perimeter.py

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+class Solution:
+    def islandPerimeter(self, grid: list[list[int]]) -> int:
+        n = len(grid)
+        m = len(grid[0])
+        dx = [0,0,1,-1]
+        dy = [1,-1,0,0]
+
+        def bfs(row, col):
+            ans = 0
+            grid[row][col] = 2
+            queue = Deque()
+            queue.append([row,col])
+
+            while queue:
+                x, y = queue.popleft()
+                perimeter = 4
+                for dirs in range(4):
+                    nx = x + dx[dirs]
+                    ny = y + dy[dirs]
+
+                    if nx < 0 or n <= nx or ny < 0 or m <= ny:
+                        continue
+                    elif 0<=nx<n and 0<=ny<m:
+                        if grid[nx][ny] == 1:
+                            queue.append([nx,ny])
+                            grid[nx][ny] = 2
+                            perimeter-=1
+                        elif grid[nx][ny] == 2:
+                            perimeter-=1
+                ans += perimeter
+            return ans
+                        
+
+        
+        for i in range(n):
+            for j in range(m):
+              if grid[i][j] == 1:
+                return bfs(i, j)  
+
+        return 0