Circular Arrays

circ.py

cases = [
    ([2,2,-1],True),
    ([3,1,2,-2],True),
    ([-4,2,4],False),
    ([9,8,8],False)
]

def is_circular_complete(case):
    key = 0
    size = len(case)
    for index in xrange(size):
        nextkey = case[key]
        if nextkey > size:
            return False
        key = (nextkey+key) % size

    if key == 0:
        return True
    return False

for case,should in cases:
    assert is_circular_complete(case) == should