如果执行下面C++代码后，输出的结果是“gesp ccf org cn ”，则横线上应填入哪个代码？
#include <iostream>
using namespace std;
int main() {
string str = "gesp.ccf.org.cn";
string delimiter = ".";
string result = "";
string token;
size_t found = str.find(delimiter);
while (found != string::npos) {
token = str.substr(0, found);
result += token;
result += " ";
__________________________ // 在此处填入代码
found = str.find(delimiter);
}
//最后一部分
result += str;
result += " ";
cout << result << endl;
return 0;
}
