Codeforces problem 750F

cf_750F_judge.py

#!/usr/bin/env python3

# Pass the path to a hack file as a command-line argument

import sys
from collections import defaultdict

fobj = open(sys.argv[1])
t = int(fobj.readline())
print(t, flush=True)

for ti in range(t):
    h = int(fobj.readline())
    print(h, flush=True)
    graph = defaultdict(list)

    for i in range(2**h - 2):
        u, v = [int(x) for x in fobj.readline().split()]
        graph[u].append(v)
        graph[v].append(u)

    root = None
    leaves_count = 0
    for u, vlist in graph.items():
        vlist.reverse()
        if len(vlist) == 2:
            if root is None:
                root = u
            else:
                raise Exception("error: Found multiple nodes with degree 2.")
        elif len(vlist) == 1:
            leaves_count += 1
        elif len(vlist) > 3:
            raise Exception("error: Found a node with degree > 3.")

    if root is None:
        raise Exception("error: Can't find a vertex with degree 2.")
    if leaves_count != 2**(h-1):
        raise Exception("error: Inconsistent number of leaves.")

    moves = 0
    while True:
        words = input().split()
        if len(words) != 2:
            print("Verdict: WA (Incorrect command format)", file=sys.stderr, flush=True)
            break
        try:
            cmd, node = words[0], int(words[1])
        except ValueError:
            print("Verdict: WA (Incorrect number format)", file=sys.stderr, flush=True)
        if cmd == '!':
            if node != root:
                print("Verdict: WA (Incorrect root)", file=sys.stderr, flush=True)
            else:
                print("Verdict: AC", file=sys.stderr, flush=True)
            break
        elif cmd == '?':
            moves += 1
            print(len(graph[node]), flush=True)
            print(*(graph[node]), flush=True)
        else:
            print("Verdict: WA (Incorrect command)", file=sys.stderr, flush=True)
    print('Moves: {}\n'.format(moves), file=sys.stderr, flush=True)