class Solution:

def restoreIpAddresses(self, s: str) -> list:

return self.convert(s)

def convert(self,s):

sz = len(s)

# Check for string size

if sz > 12:

return []

snew = s

l = []

# Generating different combinations.

for i in range(1, sz - 2):

for j in range(i + 1, sz - 1):

for k in range(j + 1, sz):

snew = snew[:k] + "." + snew[k:]

snew = snew[:j] + "." + snew[j:]

snew = snew[:i] + "." + snew[i:]

# Check for the validity of combination

if self.is_valid(snew):

l.append(snew)

snew = s

return l

def is_valid(self,ip):

# Splitting by "."

ip = ip.split(".")

# Checking for the corner cases

for i in ip:

if (len(i) > 3 or int(i) < 0 or

int(i) > 255):

return False

if len(i) > 1 and int(i) == 0:

return False

if (len(i) > 1 and int(i) != 0 and

i[0] == '0'):

return False

return True