输出ip最后一个点之后的数字

#include "stdafx.h"
#include <iostream>
#include <ctime>
#include <cstring>
#include <cmath>
#include <iostream>  
#include <string>  
#include <WinSock.h>  
#include <fstream>  
//#pragma comment(lib,"ws2_32.lib")
using namespace  std;
//bool sort(char * num,int totalNum);

void _tmain(int argc, _TCHAR* argv[])
{

      string IP1="172.16.26.29";

      string IP2="172.16.26.169";

      string IP3="172.16.223.23";

      string ss0=IP1.substr(IP1.find_last_of('.')+1,3);

      string ss1=IP2.substr(IP2.find_last_of('.')+1,3);

      string ss2=IP3.substr(IP3.find_last_of('.')+1,3);

      string ss3=IP2.substr(IP2.find_last_of('.')+1);    //当不给定第二个参数的时候，默认输出到末尾

     cout<<ss0<<endl;

     cout<<ss1<<endl;

     cout<<ss2<<endl;

     cout<<ss3<<endl;

}

输出：29

        169

        23

        169