# BOJ - 14567 - 선수과목 (Prerequisite)

Updated:

```
import sys
from collections import deque
def solution():
N, M = map(int, sys.stdin.readline().split())
graph = [[] for _ in range(N+1)]
degree = [0] * (N+1)
time = [0] * (N+1)
dq = deque()
for _ in range(M):
A, B = map(int, sys.stdin.readline().split())
graph[A].append(B)
degree[B] += 1
for i in range(1, N + 1):
if degree[i] == 0:
dq.append((i, 1))
while dq:
idx, t = dq.popleft()
time[idx] = t
for j in graph[idx]:
degree[j] -= 1
if degree[j] == 0:
dq.append((j, t+1))
for t in range(1, len(time)):
print(time[t], end=' ')
solution()
```

https://www.acmicpc.net/problem/14567

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