重载流运算符

#include <iostream>#include <vector>#include <string>#include <algorithm>using namespace std;class Student{public:int id;string name, grade;Student(){};Student(int id, string name, string grade);friendistream & operator >> (istream & in, Student & s);friend ostream & operator << (ostream & out, Student & s);bool operator < (const Student & s) const;};istream & operator >> (istream & in, Student & s){in >> s.id >> s.name >> s.grade;return in;}ostream & operator << (ostream & out, Student & s){out << s.id << " " << s.name << " " << s.grade << endl;return out;}bool Student:: operator < (const Student & s) const{return this->id < s.id;}/*请在这里填充代码*/int main(){vector<Student> sv;Student temp;while (cin >> temp){sv.push_back(temp);}sort(sv.begin(), sv.end());for (int i = 0; i < sv.size(); ++i)cout << sv[i];return 0;}