C++学生成绩管理系统

标签：vat   break   学生   getchar   algorithm   void   sort   puts   上层   

#include <map>
#include <vector>
#include <string>
#include <cstdio>
#include <iostream>
#include <algorithm>
class Courses
{
private:
    std::map<std::string, int> c;   //课程名字到编号的映射,编号从0开始
    std::vector<std::string> names; //课程编号到名字的映射
public:
    int getNum() { return c.size(); } //课程总数
    int addCourse(std::string name)   //返回新ID
    {
        int temp = c.size();
        c[name] = temp;
        names.push_back(name);
        return temp;
    }
    int findCourseId(std::string name) //课程名字寻找课程ID,找不到返回-1
    {
        if (c.find(name) != c.end())
            return c[name];
        else
            return -1;
    }
    std::string queryName(int id) //询问课程名称
    {
        if (id < 0 || id >= c.size())
            return std::string("");
        return names[id];
    }
    void display() //输出表头
    {
        printf("\t");
        for (auto i : names)
            printf("%s\t", i.c_str());
        printf("总分\t平均分\t排名\n");
    }
} courses;

class Student
{
private:
    std::string name;
    std::map<int, double> score;
    double totScore = 0;
public:
    bool operator<(const Student &x) const
    { //输出时候除以课程总数就行了courses.getNum()
        return totScore > x.totScore;
    }
    friend class Students;
};

class Students
{
private:
    std::map<std::string, int> mp; //名字到下标的映射
    std::vector<Student> s;        //下标到名字的映射
public:
    int getNum(){return s.size();}
    int findName(std::string name)
    {
        std::map<std::string, int>::iterator it = mp.find(name);
        if (it == mp.end()) return 0;
        return it->second;
    }
    void addStudent(std::string name) //录入学生成绩
    {
        Student temp;
        temp.name = name;
        int totCourse = courses.getNum();
        for(int i=0;i<totCourse;i++)
        {
            std::cout<<"请输入"<<courses.queryName(i)<<"成绩:"<<std::endl;
            double ss;
            std::cin>>ss;
            temp.score[i]=ss;
            temp.totScore+=ss;
        }
        s.push_back(temp);
        mp[name] = mp.size();
        return; //成功
    }
    double queScore(std::string name,int courseId)
    {
        std::map<std::string, int>::iterator it = mp.find(name);
        if (it == mp.end())
            return -1.0;
        int sid=it->second;
        return s[sid].score[courseId];
    }
    bool changeScore(std::string name, int courseId, double newscore) //返回是否成功
    {
        std::map<std::string, int>::iterator it = mp.find(name);
        if (it == mp.end())
            return false;
        int sid = it->second;
        int temp = s[sid].score[courseId];
        s[sid].score[courseId] = newscore;
        s[sid].totScore += newscore - temp;
        return true;
    }
    void displayStudent(std::string name) //输出一个学生的成绩,不输出表头
    {
        int sid = mp[name];
        displayStudent(sid);
    }
    void displayStudent(int sid)     //输出一个学生的成绩,不输出表头
    {
        std::cout<<s[sid].name<<"\t";
        for (int i = 0; i < courses.getNum(); i++)
        {
            printf("%.1f\t", s[sid].score[i]);
        }
        printf("%.1f\t%.1f\t%d/%u\n", s[sid].totScore, s[sid].totScore / courses.getNum(), sid + 1, mp.size());
    }
    
    void sort()
    {
        std::sort(s.begin(), s.end());
        int temp = 0;
        for (auto i : s)
        {
            mp[i.name] = temp++; //重排mp
        }
    }
} students;

class FrontPage{
private:
    inline void read(int &x)
    {
        int s = 0, w = 1;
        char ch = getchar();
        while (ch < '0' || ch > '9')
        {
            if (ch == '-')
                w = -1;
            ch = getchar();
        }
        while (ch >= '0' && ch <= '9')
            s = s * 10 + ch - '0', ch = getchar();
        x = s * w;
    }
    int temp;
public:
    void run()
    {
        printf("启动中");
        for (int i = 1; i <= 5; i++)
            system("sleep 0.1"), printf(".");
        system("cls");
        printf("欢迎使用成绩管理系统!\n请输入科目数量：\n");
        read(temp);
        puts("请输入每个科目的名称，用回车键分隔");
        for(int i=0;i<temp;i++)
        {
            std::string name;
            std::cin>>name;
            courses.addCourse(name);
        }
        puts("请输入学生数量");
        read(temp);
        puts("开始录入成绩");
        for(int i=1;i<=temp;i++)
        {
            std::string name;
            puts("输入姓名：");
            std::cin>>name;
            students.addStudent(name);
            puts("添加成功");
        }
        students.sort();
        while (1)
        {
            puts("添加学生请输入1\n修改学生成绩请输入2\n查询某学生成绩请输入3\n按排名输出成绩单请输入4");
            int type = 0;
            read(type); //提高容错性
            if (type == 1)
            {
                std::string name;
                puts("输入姓名：");
                std::cin>>name;
                students.addStudent(name);
                puts("添加成功");
                students.sort();
                system("sleep 2");
                system("cls");
                continue;
            }
            if (type == 2)
            {
                std::string name;
                puts("姓名：");
                std::cin >> name;
                if(!students.findName(name))
                {
                    puts("查无此人");
                    system("sleep 2");
                    system("cls");
                    continue;
                }
                puts("要修改的科目名称：");
                std::string cour;
                int courid;
                while (1)
                {
                    std::cin>>cour;
                    if(cour==std::string("@$#")) goto cao;
                    courid = courses.findCourseId(cour);
                    if(courid==-1)
                    {
                        puts("查无此科目,请重新输入。返回上层请输入@$#");
                    }
                    else break;
                }
                std::cout<< "原先成绩为" << students.queScore(name, courid)<<",请输入新的成绩：" << std::endl;
                double newsc;
                std::cin>>newsc;
                students.changeScore(name,courid,newsc);
                puts("修改成功");
                students.sort();
                system("sleep 2");
                cao:
                system("cls");
                continue;
            }
            if(type==3)
            {
                std::string name;
                puts("输入姓名：");
                std::cin>>name;
                courses.display();
                students.displayStudent(name);
                continue;
            }
            if(type==4)
            {
                courses.display();
                for(int i=0,sz=students.getNum();i<sz;i++)
                {
                    students.displayStudent(i);
                }
                continue;
            }
            puts("输入错误");
            system("sleep 2");
        }
    }
};

int main()
{
    FrontPage p;
    p.run();
    return 0;
}

C++学生成绩管理系统

标签：vat   break   学生   getchar   algorithm   void   sort   puts   上层   

原文地址：https://www.cnblogs.com/wawcac-blog/p/12045257.html