不知道写了点啥～，但细心值又上升了！

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

struct Student {
  /** 考号 */
  string reg_number;
  /** 参加考试的地区编号 */
  int region_id;
  /** 学生参加考式的成绩 */
  int score;
  /** 全球排名 */
  int final_rank;
  /** 地区排名 */
  int local_rank;
  // (考分高的排在前面，如果考分相同考号小的排在前面)
  bool operator<(Student& other) {
    return score == other.score ? reg_number < other.reg_number : score > other.score;
  }
};

struct Region_Info {
  /** 地区ID */ 
  int id;
  /** 该地区参加考试的总人数 */
  int nums;
  /** 该地区参加考试的所有学生 */
  vector<Student> students;

  // 计算排名 
  void caculate_local_rank() {

    sort(begin(students), end(students));

    int rank = 1; 
    for (int i = 0; i < students.size(); ++i) {
      if (i == 0) {
        students[i].local_rank = rank;
        continue;
      }
      if (students[i].score == students[i - 1].score)
         students[i].local_rank = rank;
      else {
        rank = i + 1;
        students[i].local_rank = rank;
      }
    }
  }

  // display function
  void info() {
    cout << "ID: " << id << " NUMS: " << nums << endl;
    cout << "Students: [" << endl;
    for (const auto& s : students)
      printf("%15s\t\t%d\t%d\n", s.reg_number.c_str(), s.score, s.local_rank);
    cout << "]" << endl;
  }
};

int n, k, score, total_num; // total_num 为所有地区参加考试的总人数
string reg_number;

vector<Student> all_students;

// 计算全球排名
void caculate_global_rank() {
  sort(begin(all_students), end(all_students));

  int rank = 1; 
  for (int i = 0; i < all_students.size(); ++i) {
    if (i == 0) {
      all_students[i].final_rank = rank;
      continue;
    }
    if (all_students[i].score == all_students[i - 1].score) {
       all_students[i].final_rank = rank;
    } else {
      rank = i + 1;
      all_students[i].final_rank = rank;
    }
  }
}

int main(void) {
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) {
    scanf("%d", &k); // 该地区有K名考生参加考式！
    total_num += k;
    Region_Info region = {i, k};
    for (int j = 0; j < k; ++j) {
      cin >> reg_number >> score;
      region.students.emplace_back(Student{reg_number, i, score});
    }

    region.caculate_local_rank();
    for (const auto& s : region.students)
      all_students.emplace_back(s);
  }
  caculate_global_rank(); // 计算全球排名
  // output
  printf("%d\n", total_num);
  for (const auto& s : all_students)
    printf("%s %d %d %d\n", s.reg_number.c_str(), s.final_rank, s.region_id, s.local_rank);

  return 0;
}