PTA 乙级 1080 MOOC期终成绩 (25 分) C++

 想着一个学号对应一个学生信息，于是就用了map来进行数据的输入，然后新建一个map来存储获得证书的学生的信息，由于map无法进行排序，所以把获取整数的数据又转换为vector进行sort排序之后进行输出

vector使用

map使用

注意

• 题中所说的如果总评分数相同则按照学号递增进行排序
• round进行四舍五入
• 学生期中成绩有0分的可能

C++

#include <iostream>
#include <string>
#include <map>
#include <cmath>
#include <vector>
#include <algorithm>

using namespace std;
struct grade {
    int mid, final, online, sum_grade;
} tmp_grade;

//sort的比较函数，总评高的在前，总评相同按学号字典序排名
bool cmp(pair<string, grade> a, pair<string, grade> b) {
    if(a.second.sum_grade == b.second.sum_grade) return a.first < b.first;
    return a.second.sum_grade > b.second.sum_grade;
}

int main() {
    int P = 0, M = 0, N = 0;
    map<string, grade> students_grade;
    map<string, grade> Certificate;
    cin >> P >> M >> N;
    tmp_grade = {-1, -1, -1, -1};
    for (int i = 0; i < P; ++i) {
        string id;
        cin >> id >> tmp_grade.online;
        students_grade.insert(pair<string, grade>(id, tmp_grade));
        tmp_grade.online = -1;                                          //每轮清除输入，方便下一次输入
    }

    for (int i = 0; i < M; ++i) {
        string id;
        cin >> id >> tmp_grade.mid;
        if (students_grade.find(id) == students_grade.end()) students_grade.insert(pair<string, grade>(id, tmp_grade));
        else students_grade[id].mid = tmp_grade.mid;                    //如果学号存在，直接输入，不存在则在map中插入
        tmp_grade.mid = -1;
    }

    for (int i = 0; i < N; ++i) {
        string id;
        cin >> id >> tmp_grade.final;
        if (students_grade.find(id) == students_grade.end()) students_grade.insert(pair<string, grade>(id, tmp_grade));
        else students_grade[id].final = tmp_grade.final;

        if (students_grade[id].mid > students_grade[id].final)
            students_grade[id].sum_grade = round(students_grade[id].mid * 0.4 + students_grade[id].final * 0.6);
        else
            students_grade[id].sum_grade = students_grade[id].final;

        if (students_grade[id].online >= 200 && students_grade[id].sum_grade >= 60)     //创建新的map来保存获取合格证书的学生
            Certificate.insert(pair<string, grade>(id, students_grade[id]));
        tmp_grade.final = -1;
    }

    vector< pair<string,grade> > v_sort(Certificate.begin(), Certificate.end());        //map无法用sort函数，于是转换为vector进行排序输出
    sort(v_sort.begin(), v_sort.end(), cmp);
    for (auto it = v_sort.begin(); it != v_sort.end(); ++it)                            //auto它不香嘛
        cout << it->first << ' ' << it->second.online << ' '
             << it->second.mid << ' ' << it->second.final << ' ' << it->second.sum_grade << endl;
    return 0;
}