[BOJ]11724_연결요소의개수

연결 요소의 개수

코드

import sys
sys.setrecursionlimit(10000)
input = sys.stdin.readline 

n,m = map(int,input().split())
graph = [[] for _ in range(n+1)]
graph[0] = [0,0]
visited = [False]*(n+1)
answer = 0
for _ in range(m):
    u,v = map(int,input().split())
    graph[u].append(v) # 연결 관계
    graph[v].append(u)

def dfs(graph,start,visited):
    visited[start] = True

    for i in graph[start] : 
        if not visited[i] : 
            dfs(graph,i,visited)

for i in range(1,n+1) : 
    if not visited[i] : 
        answer += 1 
        dfs(graph,i,visited)

print(answer)