Problem p03026 (python)

Fixed submission:
#!/usr/bin/env python
"""<https://github.com/cheran-senthil/PyRival>"""
from __future__ import division, print_function

import os
import sys
from io import BytesIO, IOBase

if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip
else:
    _str = str
    str = lambda x=b"": x if type(x) is bytes else _str(x).encode()


def main():
    N = read_int()
    g = [[] for _ in range(N)]
    for _ in range(N-1):
        a, b = read_int_array()
        g[a-1].append(b-1)
        g[b-1].append(a-1)
    C = read_int_array()
    C.sort()
    labels = [None]*N
    labels[0] = C.pop()
    M = sum(C)
    q = [0]
    for x in q:
        for ch in g[x]:
            if labels[ch] is None:
                q.append(ch)
                labels[ch] = C.pop()

    print(M)
    print(' '.join(map(str, labels)))





# region fastio

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        if self.buffer.tell():
            return self.buffer.read()
        return os.read(self._fd, os.fstat(self._fd).st_size)

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", b" "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", b"\n"))
    if kwargs.pop("flush", False):
        file.flush()


sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
input = lambda: sys.stdin.readline().rstrip(b"\r\n")


def read():
    return input()


def read_array(sep=None, maxsplit=-1):
    return read().split(sep, maxsplit)


def read_int():
    return int(read())


def read_int_array(sep=None, maxsplit=-1):
    return [int(a) for a in read_array(sep, maxsplit)]

# endregion

if __name__ == "__main__":
    main()

Buggy submission (verdict: Runtime Error):
#!/usr/bin/env python
"""<https://github.com/cheran-senthil/PyRival>"""
from __future__ import division, print_function

import os
import sys
from io import BytesIO, IOBase

if sys.version_info[0] < 3:
    from __builtin__ import xrange as range
    from future_builtins import ascii, filter, hex, map, oct, zip
else:
    _str = str
    str = lambda x=b"": x if type(x) is bytes else _str(x).encode()


def main():
    N = read_int()
    g = [[] for _ in range(N)]
    for _ in range(N-1):
        a, b = read_int_array()
        g[a-1].append(b-1)
        g[b-1].append(a-1)
    C = read_int_array()
    C.sort()
    labels = [None]*N
    labels[0] = C.pop()
    M = sum(C)
    q = [0]
    for x in q:
        for ch in g[x]:
            if labels[ch] is None:
                q.append(ch)
                labels[ch] = C.pop()

    print(M)
    print(' '.join(map(_str, labels)))





# region fastio

BUFSIZE = 8192


class FastIO(IOBase):
    newlines = 0

    def __init__(self, file):
        self._fd = file.fileno()
        self.buffer = BytesIO()
        self.writable = "x" in file.mode or "r" not in file.mode
        self.write = self.buffer.write if self.writable else None

    def read(self):
        if self.buffer.tell():
            return self.buffer.read()
        return os.read(self._fd, os.fstat(self._fd).st_size)

    def readline(self):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, BUFSIZE))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()

    def flush(self):
        if self.writable:
            os.write(self._fd, self.buffer.getvalue())
            self.buffer.truncate(0), self.buffer.seek(0)


def print(*args, **kwargs):
    """Prints the values to a stream, or to sys.stdout by default."""
    sep, file = kwargs.pop("sep", b" "), kwargs.pop("file", sys.stdout)
    at_start = True
    for x in args:
        if not at_start:
            file.write(sep)
        file.write(str(x))
        at_start = False
    file.write(kwargs.pop("end", b"\n"))
    if kwargs.pop("flush", False):
        file.flush()


sys.stdin, sys.stdout = FastIO(sys.stdin), FastIO(sys.stdout)
input = lambda: sys.stdin.readline().rstrip(b"\r\n")


def read():
    return input()


def read_array(sep=None, maxsplit=-1):
    return read().split(sep, maxsplit)


def read_int():
    return int(read())


def read_int_array(sep=None, maxsplit=-1):
    return [int(a) for a in read_array(sep, maxsplit)]

# endregion

if __name__ == "__main__":
    main()