int mian()
{
// 初始化
std::map<std::string, std::vector<int>> a = {{"pos", {}},
{"zhi", {}}};
std::map<std::string, std::vector<int>>::iterator it = a.find("pos");
std::cout << it->second.size() << std::endl;
it->second.push_back(1);
std::cout << it->second.size() << std::endl;
}