Snakeless path

from collections import deque


def find_snakeless_path(n, snake_edges):
    snake_set = set()
    for a, b in snake_edges:
        snake_set.add((a, b))
        snake_set.add((b, a))

    # Build adjacency list
    adj = [[] for _ in range(n + 1)]
    for u in range(1, n + 1):
        for v in range(1, n + 1):
            if u != v and (u, v) not in snake_set:
                adj[u].append(v)

    # BFS to find path from 1 to n
    queue = deque([1])
    visited = [False] * (n + 1)
    parent = [-1] * (n + 1)
    visited[1] = True

    while queue:
        node = queue.popleft()
        if node == n:
            break
        for nxt in adj[node]:
            if not visited[nxt]:
                visited[nxt] = True
                parent[nxt] = node
                queue.append(nxt)

    # unable to reach the end
    if not visited[n]:
        print(0)
        return

    # Reconstruct path
    path = []
    cur = n
    while cur != -1:
        path.append(cur)
        cur = parent[cur]
    path.reverse()

    print(len(path))
    print(" ".join(map(str, path)))


if __name__ == "__main__":
    n, m = map(int, input().split())
    snakes = []
    for i in range(n):
        start, end = map(int, input().split())
        snakes.append((start, end))

    find_snakeless_path(n, snakes)


# 5 5
# 1 2
# 1 3
# 1 5
# 2 5
# 3 5

Test 1

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 4

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 5

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 6

Verdict: ACCEPTED

Test 7

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 8

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 9

Verdict: ACCEPTED

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 17

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 18

Verdict: ACCEPTED

Test 19

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 20

Verdict: WRONG ANSWER

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 27

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 30

Verdict: WRONG ANSWER

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: WRONG ANSWER

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 38

Verdict: ACCEPTED

Test 39

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 40

Verdict: WRONG ANSWER

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 48

Verdict: ACCEPTED

Test 49

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 50

Verdict: WRONG ANSWER

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 60

Verdict: WRONG ANSWER

Test 61

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 62

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 63

Verdict: ACCEPTED

Test 64

Verdict: WRONG ANSWER

Test 65

Verdict: ACCEPTED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED

Test 69

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 70

Verdict: TIME LIMIT EXCEEDED

Test 71

Verdict: TIME LIMIT EXCEEDED

Test 72

Verdict: TIME LIMIT EXCEEDED

Test 73

Verdict: TIME LIMIT EXCEEDED

Test 74

Verdict: TIME LIMIT EXCEEDED

Test 75

Verdict: TIME LIMIT EXCEEDED

Test 76

Verdict: TIME LIMIT EXCEEDED

Test 77

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 78

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 79

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 80

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 81

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 82

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 83

Verdict: TIME LIMIT EXCEEDED

Test 84

Verdict: TIME LIMIT EXCEEDED

Test 85

Verdict: TIME LIMIT EXCEEDED

Test 86

Verdict: TIME LIMIT EXCEEDED

Test 87

Verdict: TIME LIMIT EXCEEDED

Test 88

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError

Test 89

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 54, in <module>
    start, end = map(int, input().split())
EOFError