[BOJ] 2606번:바이러스

■ 문제풀이

1) dfs 알고리즘

 

■ 해답

n = int(input())
m = int(input())

graph = [[] for _ in range(n + 1)]
for i in range(m):
    a, b = map(int, input().split())
    graph[a].append(b)
    graph[b].append(a)
    graph[a].sort()
    graph[b].sort()

visited = [False] * (n + 1)
    
cnt = 0
def dfs(graph, v, visited):
    global cnt
    visited[v] = True
    for i in graph[v]:
        if not visited[i]:
            cnt += 1
            dfs(graph, i, visited)
            
dfs(graph, 1, visited)
print(cnt)

출처 : https://www.acmicpc.net/problem/2606

2606번: 바이러스