C++11 正则匹配

C++11 正则的一些基本语法参考
http://blog.youkuaiyun.com/berguiliu/article/details/25831925

• C++11标准 STL正则表达式 验证电子邮件地址

http://www.cnblogs.com/yejianfei/archive/2012/10/07/2713715.html

• C++11 正则验证 IPv4， IPv6
  ipv4的
  http://blog.youkuaiyun.com/u012806692/article/details/50635590

leetcode 468 Validate IP Address
题目地址：
https://leetcode.com/problems/validate-ip-address/#/description

ac代码：

class Solution {
public:

    bool isIPv4(string IP)
    {
        string s = "^(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|[1-9])\\.";
            s += "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)\\.";
            s += "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)\\.";
            s += "(1\\d{2}|2[0-4]\\d|25[0-5]|[1-9]\\d|\\d)$";

        regex pattern(s);

        std::match_results<std::string::const_iterator> result;
        bool valid = regex_match(IP, result, pattern);
        if(valid&&(result.length()>0))
        {
            /*for(int i =0;i<result.length();i++)
            {
                cout<<result[i]<<endl;
            }*/
            return true;
        }

        return valid;
    }

    bool isIPv6(string IP)
    {
        string s = "^([0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";
            s += "(:[0-9a-fA-F]{1,4})";

        regex pattern(s);

        std::match_results<std::string::const_iterator> result;
        bool valid = regex_match(IP, result, pattern);
        if(valid&&(result.length()>0))
        {
            /*for(int i =0;i<result.length();i++)
            {
                cout<<result[i]<<endl;
            }*/
            return true;
        }

        return valid;
    }

    string validIPAddress(string IP) {

        if(isIPv4(IP))
            return "IPv4";

        if(isIPv6(IP))
            return "IPv6";

        return "Neither";
    }
};