[23.01.09/Python] 바이러스

Author: par3k

Python_BOJ_2023/2606.py

@@ -0,0 +1,26 @@
+#  바이러스
+import sys
+input = lambda: sys.stdin.readline()
+
+n = int(input())
+m = int(input())
+graph = [[] for _ in range(n + 1)]
+for _ in range(m):
+    x, y = map(int, input().split())
+    graph[x].append(y)
+    graph[y].append(x)
+
+ans = 0
+visited = [0] * (n + 1)
+
+def dfs(node):
+    global ans
+    visited[node] = 1
+    graph[node].sort()
+    for next_node in graph[node]:
+        if not visited[next_node]:
+            dfs(next_node)
+            ans += 1
+
+dfs(1)
+print(ans)