백준 / 2252번 / 줄 세우기 / python 파이썬

 

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

 

 

 

 

 

 

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나의 풀이

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

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

result = []

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

    for next in graph[now]:
        indegree[next] -= 1

        if indegree[next] == 0:
            queue.append(next)

print(*result)

 

 

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