from queue import Queue

class Graph:
    def __init__(self, vertex_num):
        # 인접 리스트로 구현
        self.adj_list = [[] for _ in range(vertex_num)]
        # 방문 여부 체크
        self.visited = [False for _ in range(vertex_num)]

    def add_edge(self, u, v):
        self.adj_list[u].append(v)
        self.adj_list[v].append(u)

    def init_visited(self):
        for i in range(len(self.visited)):
            self.visited[i] = False