apstraTask.py

"""Minimal subnetwork."""

def minSubNetMask(ips):
    m = 0
    for ip in ips: m |= ips[0] ^ ip
    full = (1 << 32) - 1 # 128 for IPv6
    return (full << m.bit_length()) & full

def tst(ips, res):
    r = minSubNetMask(ips) == res
    if not r:
        s = "error - min subnet mask of ips:\n"
        for ip in ips: s += str(bin(ip)) + "\n"
        print(s + "not equals to:\n" + str(bin(res)) + "\n")
    return r

res = True

res = res and tst([],
    0b11111111111111111111111111111111)

res = res and tst([
    0b10010101100111010010011001110111],
    0b11111111111111111111111111111111)

res = res and tst([
    0b10010101100111010010011001110111,
    0b10010101100111010010011001110111],
    0b11111111111111111111111111111111)

res = res and tst([
    0b10010101100111010010011001110111,
    0b10010101100111010010011001110110],
    0b11111111111111111111111111111110)

res = res and tst([
    0b10010101100111010010011001110111,
    0b00010101100111010010011001110111],
    0b00000000000000000000000000000000)

res = res and tst([
    0b10010101100111010010011001110111,
    0b10110101100111010010011001110111],
    0b11000000000000000000000000000000)

res = res and tst([
    0b10010101100111010010011001110111,
    0b10010101100111010010001001110111,
    0b10010101100111010010011011100111,
    0b10010101100111010010011101100101],
    0b11111111111111111111100000000000)

res = res and tst([
    0b10010101100111010010011001110111,
    0b10010101100111010010001001110111,
    0b10010101100111010010011011100111,
    0b10010101100111010010011101100101,
    0b10010101100110010010011001110111],
    0b11111111111110000000000000000000)

print("All tests are passed" if res else "Tests are failed")