평범한 위상정렬 import sys input = sys.stdin.readline from collections import deque def topological_sort(): visited = {i: False for i in range(1, N + 1)} q = deque() for node in levels: if not levels[node]: q.append(node) visited[node] = True while q: cur_node = q.popleft() for next_node in next_nodes[cur_node]: levels[next_node] -= 1 if not visited[next_node] and not levels[next_node]: visited[next_no..