[백준] 14500번 줄 세우기(위상 정렬) - 파이썬

https://www.acmicpc.net/problem/2252

2252번: 줄 세우기

import sys
from collections import deque

n, m = map(int,sys.stdin.readline().split())

indegree = [0] * (n+1)
graph = [[] for i in range(n+1)]

for _ in range(m):
    a, b = map(int,sys.stdin.readline().split())
    graph[a].append(b)
    indegree[b] += 1

def topology_sort():
    result = []
    q = deque()

    for i in range(1,n+1):
        if indegree[i] == 0:
            q.append(i)

    while q:
        now = q.popleft()
        result.append(now)

        for i in graph[now]:
            indegree[i] -= 1
            if indegree[i] == 0:
                q.append(i)

    for i in result:
        print(i,end = ' ')

topology_sort()

위상정렬의 대표적인 예이다.

꼭 숙지해두자

https://zoozoozoo.tistory.com/411

위상 정렬