题目：
题解：
class Solution:
def validIPAddress(self, queryIP: str) -> str:
if queryIP.find(".") != -1:
# IPv4
last = -1
for i in range(4):
cur = (len(queryIP) if i == 3 else queryIP.find(".", last + 1))
if cur == -1:
return "Neither"
if not 1 <= cur - last - 1 <= 3:
return "Neither"
addr = 0
for j in range(last + 1, cur):
if not queryIP[j].isdigit():
return "Neither"
addr = addr * 10 + int(queryIP[j])
if addr > 255:
return "Neither"
if addr > 0 and queryIP[last + 1] == "0":
return "Neither"
if addr == 0 and cur - last - 1 > 1:
return "Neither"
last = cur
return "IPv4"
else:
# IPv6
last = -1
for i in range(8):
cur = (len(queryIP) if i == 7 else queryIP.find(":", last + 1))
if cur == -1:
return "Neither"
if not 1 <= cur - last - 1 <= 4:
return "Neither"
for j in range(last + 1, cur):
if not queryIP[j].isdigit() and not("a" <= queryIP[j].lower() <= "f"):
return "Neither"
last = cur
return "IPv6"
