leetcode_468

Given a string IP, return "IPv4" if IP is a valid IPv4 address, "IPv6" if IP is a valid IPv6 address or "Neither" if IP is not a correct IP of any type.

A valid IPv4 address is an IP in the form "x1.x2.x3.x4" where 0 <= xi <= 255 and xi cannot contain leading zeros. For example, "192.168.1.1" and "192.168.1.0" are valid IPv4 addresses but "192.168.01.1", while "192.168.1.00" and "192.168@1.1" are invalid IPv4 addresses.

A valid IPv6 address is an IP in the form "x1:x2:x3:x4:x5:x6:x7:x8" where:

1 <= xi.length <= 4 xi is a hexadecimal string which may contain digits, lower-case English letter ('a' to 'f') and upper-case English letters ('A' to 'F'). Leading zeros are allowed in xi. For example, "2001:0db8:85a3:0000:0000:8a2e:0370:7334" and "2001:db8:85a3:0:0:8A2E:0370:7334" are valid IPv6 addresses, while "2001:0db8:85a3::8A2E:037j:7334" and "02001:0db8:85a3:0000:0000:8a2e:0370:7334" are invalid IPv6 addresses.

Example 1:

Input: IP = "172.16.254.1" Output: "IPv4" Explanation: This is a valid IPv4 address, return "IPv4". Example 2:

Input: IP = "2001:0db8:85a3:0:0:8A2E:0370:7334" Output: "IPv6" Explanation: This is a valid IPv6 address, return "IPv6". Example 3:

Input: IP = "256.256.256.256" Output: "Neither" Explanation: This is neither a IPv4 address nor a IPv6 address. Example 4:

Input: IP = "2001:0db8:85a3:0:0:8A2E:0370:7334:" Output: "Neither" Example 5:

Input: IP = "1e1.4.5.6" Output: "Neither"

Constraints:

IP consists only of English letters, digits and the characters '.' and ':'.

Solutions

1. straight forward

class Solution:
    def validIPAddress(self, IP: str) -> str:
        def is_ipv4(ip):
            try:
                ds = [int(ip) for ip in IP.split('.') if ip[0] != '0' or len(ip) == 1]
            except:
                return False
            return len([d for d in ds if 0 <= d <= 255]) == 4;
        def is_ipv6(ip):
            try:
                ds = [int(ip, 16) for ip in IP.split(':') if len(ip) <= 4]
            except:
                return False
            return len(ds) == 8
        if IP.count('.') == 3:
            return "IPv4" if is_ipv4(IP) else "Neither"
        elif IP.count(':') == 7:
            return "IPv6" if is_ipv6(IP) else "Neither"
        else:
            return "Neither"

1. regex

2. Needs to be DONE

3. builtin api