468. Validate IP Address

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 ':'.

Rust Solution

struct Solution;

use std::net::Ipv4Addr;
use std::net::Ipv6Addr;

impl Solution {
    fn valid_ip_address(ip: String) -> String {
        if Self::is_ipv4(&ip) {
            return "IPv4".to_string();
        }
        if Self::is_ipv6(&ip) {
            return "IPv6".to_string();
        }
        "Neither".to_string()
    }

    fn is_ipv4(ip: &str) -> bool {
        if let Ok(v4) = ip.parse::<Ipv4Addr>() {
            v4.to_string() == ip
        } else {
            false
        }
    }

    fn is_ipv6(ip: &str) -> bool {
        if ip.split(':').any(|p| p.is_empty()) {
            return false;
        }
        ip.parse::<Ipv6Addr>().is_ok()
    }
}

#[test]
fn test() {
    let ip = "172.16.254.1".to_string();
    let res = "IPv4".to_string();
    assert_eq!(Solution::valid_ip_address(ip), res);
    let ip = "2001:0db8:85a3:0:0:8A2E:0370:7334".to_string();
    let res = "IPv6".to_string();
    assert_eq!(Solution::valid_ip_address(ip), res);
    let ip = "256.256.256.256".to_string();
    let res = "Neither".to_string();
    assert_eq!(Solution::valid_ip_address(ip), res);
    let ip = "01.01.01.01".to_string();
    let res = "Neither".to_string();
    assert_eq!(Solution::valid_ip_address(ip), res);
    let ip = "2001:db8:85a3:0::8a2E:0370:7334".to_string();
    let res = "Neither".to_string();
    assert_eq!(Solution::valid_ip_address(ip), res);
}

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