一、题目内容

二、题解

解法1：

思路

代码

public class Solution {
    public String solve (String IP) {
        // write code here
        return validIPv4(IP) ? "IPv4" : (validIPv6(IP) ? "IPv6" : "Neither");
    }
    private boolean validIPv4(String IP){
        String[] strs = IP.split("\\.", -1);
        if(strs.length!=4){
            return false;
        }
        for(String str:strs){
            if (str.length() > 1 && str.startsWith("0")) {
                return false;
            }
            try {
                int val = Integer.parseInt(str);
                if (!(val >= 0 && val <= 255)) {
                    return false;
                }
            } catch (NumberFormatException numberFormatException) {
                return false;
            }
        }
        return true;
    }
    private boolean validIPv6(String IP) {
        String[] strs = IP.split(":", -1);
        if (strs.length != 8) {
            return false;
        }
        for (String str : strs) {
            if (str.length() > 4 || str.length() == 0) {
                return false;
            }
            try {
                int val = Integer.parseInt(str, 16);
            } catch (NumberFormatException numberFormatException) {
                return false;
            }
        }
        return true;
    }
}