解法一：排序

自定义排序规则。Java最后一个点一直被卡，换C++。

#include <bits/stdc++.h>
using namespace std;
class Student {
public:
    string id;
    string name;
    int score;
public:
    Student() {}
    Student(const string &id, const string &name, int score) : id(id), name(name), score(score) {}
    static bool cmp1(Student o1, Student o2) {
        return o1.id < o2.id;
    }
    static bool cmp2(Student o1, Student o2) {
        if (o1.name == o2.name) {
            return o1.id < o2.id;
        } else {
            return o1.name < o2.name;
        }
    }
    static bool cmp3(Student o1, Student o2) {
        if (o1.score == o2.score) {
            return o1.id < o2.id;
        } else {
            return o1.score < o2.score;
        }
    }
};
Student students[100005];
int main() {
    ios::sync_with_stdio(false);
    int N, C;
    cin >> N >> C;
    string id;
    string name;
    int score;
    for (int i = 0; i < N; ++i) {
        cin >> id >> name >> score;
        students[i] = Student(id, name, score);
    }
    switch (C) {
        case 1:
            sort(students, students + N, Student::cmp1);
            break;
        case 2:
            sort(students, students + N, Student::cmp2);
            break;
        case 3:
            sort(students, students + N, Student::cmp3);
    }
    for (int i = 0; i < N; ++i) {
        cout << students[i].id << " " << students[i].name << " " << students[i].score << '\n';
    }
    return 0;
}