import re


def normalize(s):
    """Return a normalized version of string s with newlines, tabs and C style comments ("/* ... */")
    replaced with spaces. Multiple spaces are replaced with a single space.

    >>> normalize("  /* nothing */   foo\tfoo  /* bar */  foo     ")
    'foo foo foo'
    """
    assert(type(s) is str)
    s = s.replace("\n", " ")
    s = s.replace("\t", " ")
    s = re.sub("/\*.*?\*/", " ", s)
    s = re.sub(" {2,}", " ", s)
    return s.strip()