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 ':'.
class Solution {
public String validIPAddress(String IP) {
String[] ipV4 = IP.split("\\.", -1);
String[] ipV6 = IP.split("\\:", -1);
if(ipV4.length == 4){
for(String s: ipV4){
if(!isIpV4(s)){
return "Neither";
}
}
return "IPv4";
}
if(ipV6.length == 8){
for(String s: ipV6){
if(!isIpV6(s)){
return "Neither";
}
}
return "IPv6";
}
return "Neither";
}
private boolean isIpV4(String s) {
try {
return String.valueOf(Integer.parseInt(s)).equals(s) && Integer.parseInt(s) <= 255 && Integer.parseInt(s) >= 0;
} catch(Exception e) {
return false;
}
}
private boolean isIpV6(String s) {
if(s.length() > 4) {
return false;
}
try {
return Integer.parseInt(s, 16) >= 0;
} catch(Exception e) {
return false;
}
}
}16进制转换：Integer.parseInt(s, 16)