[BOJ] #17141. 연구소2 / 골드4 / 1시간 / 실패

Author: Mingguriguri

minjeong/DFSBFS/2025-10-19-[백준]-#17141-연구소2.py

@@ -0,0 +1,55 @@
+import sys
+from collections import deque
+from itertools import combinations
+
+# 상, 하, 좌, 우
+dx = [-1, 1, 0, 0]
+dy = [0, 0, -1, 1]
+
+input = sys.stdin.readline
+answer = float("inf")  # 최솟값을 찾기 위해 초깃값을 inf로 설정
+
+
+def bfs(v):
+    queue = deque(v)
+    visited = [[-1 for _ in range(N)] for _ in range(N)]
+    min_value = 0  # 최소 횟수를 찾기 위한 변수
+    for x, y in queue:
+        visited[x][y] = 0
+    while queue:
+        x, y = queue.popleft()
+        for i in range(4):
+            ax = x + dx[i]
+            ay = y + dy[i]
+            if 0 <= ax < N and 0 <= ay < N:
+                if visited[ax][ay] == -1 and board[ax][ay] != 1:
+                    queue.append([ax, ay])
+                    visited[ax][ay] = visited[x][y] + 1
+                    min_value = max(min_value, visited[x][y] + 1)
+
+    for i in range(N):
+        for j in range(N):
+            if visited[i][j] == -1 and board[i][j] != 1:
+                return float("inf")
+    return min_value
+
+
+N, M = map(int, input().split())
+board = [list(map(int, input().split())) for _ in range(N)]
+virus = []
+
+# 바이러스의 좌표 찾기
+for i in range(N):
+    for j in range(N):
+        if board[i][j] == 2:
+            virus.append([i, j])
+
+# 바이러스 좌표들 중 M개를 뽑아 BFS 수행
+for v in combinations(virus, M):
+    answer = min(bfs(v), answer)
+
+# 정답 반환
+if answer == float("inf"):
+    print(-1)
+else:
+    print(answer)