[백준] 2623번 음악프로그램 파이썬 코드

코드

from collections import deque
import sys

input = sys.stdin.readline
n,m = map(int, input().split())
graph = [[] for _ in range(n+1)]
indegree = [0]*(n+1)

for i in range(1,m+1):
  lst = [*map(int, input().split())]
  for j in range(1,lst[0]):
    graph[lst[j]].append(lst[j+1])
    indegree[lst[j+1]] += 1

def topol_sort():
  queue = deque()
  sequence = []
  for i in range(1, n+1):
    if indegree[i] == 0:
      queue.append(i)
  while queue:
    popnum = queue.popleft()
    sequence.append(popnum)
    for j in graph[popnum]:
      indegree[j] -= 1
      if indegree[j] == 0:
        queue.append(j)
  return sequence

stagesequence = topol_sort()
print(0) if n!= len(stagesequence) else print(*stagesequence, sep='\n')