[23.01.29/Python] 안전 영역

Author: par3k

Python_BOJ_2023/2468.py

@@ -0,0 +1,44 @@
+# 안전 영역
+from collections import deque
+import sys
+input = lambda: sys.stdin.readline()
+n = int(input())
+graph = [list(map(int, input().split())) for _ in range(n)]
+max_height = max(max(graph))
+
+answer = list()
+dx, dy = [-1, 1, 0, 0], [0, 0, -1, 1]
+
+def bfs(x, y):
+    queue = deque()
+    queue.append((x, y))
+    visited[x][y] = True
+    while queue:
+        xx, yy = queue.popleft()
+        for i in range(4):
+            nx, ny = xx + dx[i], yy + dy[i]
+            if 0 <= nx < n and 0 <= ny < n:
+                if not visited[nx][ny] and graph[nx][ny] > 0:
+                    queue.append((nx, ny))
+                    visited[nx][ny] = True
+
+def decreasing_height():
+    for i in range(n):
+        for j in range(n):
+            if graph[i][j] > 0:
+                graph[i][j] -= 1
+
+while max_height > 0:
+    visited = [[False] * n for _ in range(n)]
+    cnt_building = 0
+    for i in range(n):
+        for j in range(n):
+            if not visited[i][j] and graph[i][j] > 0:
+                bfs(i, j)
+                cnt_building += 1
+    
+    answer.append(cnt_building)
+    max_height -= 1
+    decreasing_height()
+
+print(max(answer))