Pavel Patsey
142 lines
4.0 KiB
Python
142 lines
4.0 KiB
Python
import cProfile
|
|
from typing import Optional
|
|
|
|
Node = tuple[int, int, int]
|
|
|
|
|
|
def get_data(input_file):
|
|
with open(input_file, "r") as file:
|
|
data = file.read().splitlines()
|
|
return data
|
|
|
|
|
|
def cidr4_to_node(cidr4: str) -> Node:
|
|
ip, mask_len = cidr4.strip().split("/")
|
|
mask_len = int(mask_len)
|
|
a, b, c, d = list(map(int, ip.split(".")))
|
|
ip_value = a * 256**3 + b * 256**2 + c * 256**1 + d * 256**0
|
|
added_ips_number = 0
|
|
return ip_value, mask_len, added_ips_number
|
|
|
|
|
|
def sort_nodes(nodes: list[Node]) -> list[Node]:
|
|
return sorted(nodes, key=lambda x: (x[1], x[0]))
|
|
|
|
|
|
def get_net_addr(ip: int, mask_len: int) -> int:
|
|
mask = ((1 << mask_len) - 1) << (32 - mask_len)
|
|
net_addr = ip & mask
|
|
return net_addr
|
|
|
|
|
|
def get_parent_mask(ip: int, mask_len: int) -> Optional[int]:
|
|
if mask_len == 0:
|
|
return None
|
|
return get_net_addr(ip, mask_len - 1)
|
|
|
|
|
|
def have_same_parent(ip_a, mask_len_a, ip_b, mask_len_b) -> bool:
|
|
return mask_len_a == mask_len_b and get_parent_mask(
|
|
ip_a, mask_len_a
|
|
) == get_parent_mask(ip_b, mask_len_b)
|
|
|
|
|
|
def get_group_with_max_mask_len(nodes: list[Node]) -> list[Node]:
|
|
max_mask_len = max(nodes, key=lambda x: x[1])[1]
|
|
return list(filter(lambda x: x[1] == max_mask_len, nodes))
|
|
|
|
|
|
def get_parent(a: Node, b: Optional[Node] = None) -> Node:
|
|
ip_a, mask_len_a, added_ips_number_a = a
|
|
ip = get_parent_mask(ip_a, mask_len_a)
|
|
mask_len = mask_len_a - 1
|
|
added_ips_number = added_ips_number_a + 2 ** (32 - mask_len_a)
|
|
if b:
|
|
ip_b, mask_len_b, added_ips_b = b
|
|
assert have_same_parent(ip_a, mask_len_a, ip_b, mask_len_b)
|
|
added_ips_number = added_ips_number_a + added_ips_b
|
|
return ip, mask_len, added_ips_number
|
|
|
|
|
|
def reduce_nodes(nodes: list[Node]) -> list[Node]:
|
|
group = get_group_with_max_mask_len(nodes)
|
|
|
|
neighbours = []
|
|
loners = []
|
|
i = 0
|
|
while i < len(group) - 1:
|
|
a, b = group[i], group[i + 1]
|
|
ip_a, mask_len_a, _ = a
|
|
ip_b, mask_len_b, _ = b
|
|
if have_same_parent(ip_a, mask_len_a, ip_b, mask_len_b):
|
|
neighbours.append((a, b))
|
|
i += 2
|
|
else:
|
|
loners.append(a)
|
|
i += 1
|
|
if i == len(group) - 1:
|
|
loners.append(group[i])
|
|
|
|
if neighbours:
|
|
zipped = zip(neighbours, map(lambda x: get_parent(x[0], x[1]), neighbours))
|
|
min_zipped = min(zipped, key=lambda x: x[1][2])
|
|
(a, b), parent = min_zipped
|
|
nodes.remove(a)
|
|
nodes.remove(b)
|
|
nodes.append(parent)
|
|
elif loners:
|
|
zipped = zip(loners, map(get_parent, loners))
|
|
min_zipped = min(zipped, key=lambda x: x[1][2])
|
|
a, parent = min_zipped
|
|
nodes.remove(a)
|
|
nodes.append(parent)
|
|
else:
|
|
assert False, "Error"
|
|
|
|
return sort_nodes(nodes)
|
|
|
|
|
|
def merge_nodes(nodes: list[Node], required_len: int) -> list[Node]:
|
|
while len(nodes) > required_len:
|
|
nodes = reduce_nodes(nodes)
|
|
return nodes
|
|
|
|
|
|
def node_to_cidr4(ip_value, mask_len) -> str:
|
|
lst = [str(ip_value >> (i << 3) & 0xFF) for i in reversed(range(4))]
|
|
ip = ".".join(lst)
|
|
return f"{ip}/{mask_len}"
|
|
|
|
|
|
def answer(nodes: list[Node], required_len: int) -> tuple[list[str], int]:
|
|
nodes = sort_nodes(nodes)
|
|
merged_nodes = merge_nodes(nodes, required_len)
|
|
|
|
cidr4s = []
|
|
sum_added_ips = 0
|
|
for ip_value, mask_len, added_ips in merged_nodes:
|
|
cidr4s.append(node_to_cidr4(ip_value, mask_len))
|
|
sum_added_ips += added_ips
|
|
return cidr4s, sum_added_ips
|
|
|
|
|
|
def main():
|
|
file = "cidr4.txt"
|
|
required_len = 20
|
|
|
|
data = get_data(file)
|
|
nodes = list(map(cidr4_to_node, data))
|
|
cidr4s, sum_added_ips = answer(nodes, required_len)
|
|
|
|
cidr4s_str = "\n".join(cidr4s)
|
|
print(
|
|
f"Исходный список длины {len(nodes)} сокращен до {len(cidr4s)}\n"
|
|
f"Количество добавленных ip адресов: {sum_added_ips:_}\n"
|
|
f"Список объединенных cidr4:\n"
|
|
f"{cidr4s_str}"
|
|
)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
cProfile.run("main()")
|