C++ 實現簡單命令行學生管理系統

貼吧ID： 這把問題不大

編譯環境是macOS。system(“clear”) 在windows下請換成 system(“cls”)

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdlib>
using namespace std;

class Student {                                                     // 學生base類
public:
    static int engSum;
    static int chiSum;
    static int matSum;
    explicit Student(string &Nname,string &NID,string &Neng,string &Nchi,string &Nmat)
            :name(Nname),ID(NID),eng_score(Neng),chi_score(Nchi),math_score(Nmat)
    { sumup();}
    const string& getID() const{ return ID; }
    const string& getName() const{ return name; }
    const string& getEng() const{ return eng_score; }
    const string& getChi() const{ return chi_score; }
    const string& getMat() const{ return math_score; }
    const int     getsum() const{ return scores_sum; }
    void          changeEng(string &newEng){ eng_score = newEng; }
    void          changeChi(string &newChi){ chi_score = newChi; }
    void          changeMat(string &newMat){ math_score = newMat; }
    void          sumup(){
        int e = stoi(eng_score); int c = stoi(chi_score); int m = stoi(math_score); scores_sum = e+c+m;
    }
private:
    string name;
    string ID;
    string eng_score;
    string chi_score;
    string math_score;
    int scores_sum;                                                 // 單個學生的成績總和
};
int Student::engSum = 0;                                            // 靜態變量，代表學生這個整體的某科成績總和
int Student::chiSum = 0;
int Student::matSum = 0;

Student* __lookup(vector<Student *>& stus,string &target);          // 核心查找函數
void     launcher();                                                // 主邏輯實現
void     display(int currentSize);                                  // 界面
void     append(vector<Student *>& stus);                           // 添加
Student* displaySingleInfo(vector<Student *>& stus,string target);  // 查找並顯示信息
void     change(vector<Student *>& stus);                           // 修改
void     del(vector<Student *>& stus);                              // 刪除
void     search(vector<Student *>& stus);                           // 查找
void     quitSys(vector<Student *>& stus);                          // 關閉並清理內存
void     displayAllInfos(vector<Student *>& stus);                  // 顯示所有學生信息,被用作子函數
bool     comp(const Student* a,const Student* b){                   // 排序依據實現
    return a->getsum()>b->getsum();
}

int main(){                                                         /**** 系統入口 ****/
    launcher();
    cout<< "再見" << endl;
    return 0;
}

// ****************************** 功能實現 ***************************************

void launcher(){
    vector<Student *> stus;
    string            _input;
    display(static_cast<int>(stus.size()));
    while(cin>>_input){
        char choice = _input.at(0);
        system("clear");                                            // 操作後清理屏幕,windows下請換成system("cls")
        switch(choice){
            case ‘A‘:append(stus);
                break;
            case ‘B‘:change(stus);
                break;
            case ‘C‘:del(stus);
                break;
            case ‘D‘:search(stus);
                break;
            case ‘E‘:displayAllInfos(stus);
                getchar();
                break;
            case ‘Q‘:quitSys(stus);
                return;
            default: cout << "無選項"<<choice<<",請重試。" << endl;
                break;
        }
        system("clear");                                            // 操作後清理屏幕,windows下請換成system("cls")
        display(static_cast<int>(stus.size()));
    }
}
void display(int currentSize){
    cout << "\n\n --------------------------------------------------------------------------------" << endl;
    cout << "| ~~~                            輸入Q退出系統                               ~~~" << endl;
    cout << " --------------------------------------------------------------------------------" << endl;
    cout << "|\n";
    cout << "|                           * 正在運行學生管理系統 *" << endl;
    cout << "|\n";
    cout << " --------------------------------------------------------------------------------" << endl;
    cout << "|" << endl;
    cout << "|              * 已記錄" << currentSize << "個學生的檔案 *       * 你還可以錄入" << 100 - currentSize
         << "個學生 *" << endl;
    cout << "|\n";
    cout << " --------------------------------------------------------------------------------" << endl;
    cout << "|\n";
    cout << "|                   接下來，你想進行什麽操作? (輸入對應序號)" << endl;
    cout << "|\n";
    cout << "|  (A).添加       (B).修改       (C).刪除       (D).查找      (E).查看所有學生檔案" << endl;
    cout << "|\n";
    cout << " --------------------------------------------------------------------------------" << endl;
    cout<< "--> ";
}
void append(vector<Student *>& stus){                                   // 添加
    cout << "\n\n好的，現在開始添加學生: \n\n";
    cout << "請輸入新學生的姓名、學號、英語成績、語文成績、數學成績\n\n"
         << "例如: 小明 1704010625 129 120 134\n";
    cout << " ------------------------------------------------------" << endl;
    cout<< "--> ";
    string n,i,e,c,m;
    cin >> n >> i >> e >> c >> m;
    Student *newStu = new Student(n,i,e,c,m);
    stus.push_back(newStu);
    Student::engSum += stoi(e); Student::chiSum += stoi(c); Student::matSum += stoi(m);
}
void change(vector<Student *>& stus){                                   // 修改
    cout << "\n\n好的，現在開始進行修改操作: \n\n";
    cout << "請輸入需要修改的學生的學號： \n"<<endl;
    cout<< "--> ";
    string target;
    cin >> target;
    Student *temp = displaySingleInfo(stus,target);
    if(temp != nullptr){
        cout << "\n你想改動" << temp->getName() << "的哪個成績？" << endl;
        cout << "(A).English  (B).Chinese  (C).Math" << endl;
        cout << "--> ";
        string _input;
        cin >> _input;
        char ch = _input.at(0);
        string tmp;
        if(ch == ‘A‘){
            cout << "請輸入新的英語成績： ";
            cin >> tmp;
            temp->changeEng(tmp);
        }else if(ch == ‘B‘){
            cout << "請輸入新的語文成績： ";
            cin >> tmp;
            temp->changeChi(tmp);
        }else{
            cout << "請輸入新的數學成績： ";
            cin >> tmp;
            temp->changeMat(tmp);
        }
    }
}
void del(vector<Student *>& stus){                                      // 刪除
    cout << "\n\n好的，現在開始進行刪除操作: \n\n";
    cout << "請輸入需要刪除的學生的學號： \n"<<endl;
    cout<< "--> ";
    string target;
    cin >> target;
    vector<Student *>::iterator it;
    bool findIt = false;
    for(it = stus.begin();it != stus.end();){
        if((*it)->getID() == target){
            findIt = true;
            Student::engSum -= stoi((*it)->getEng());
            Student::chiSum -= stoi((*it)->getChi());
            Student::matSum -= stoi((*it)->getMat());
            it = stus.erase(it);
        }else
            ++it;
    }
    if(!findIt)
        cout << "未查找到，請重試！" << endl;
}
void search(vector<Student *>& stus){                                   // 查找
    cout << "\n\n好的，現在開始進行查找操作: \n\n";
    cout << "請輸入需要查找的學生的學號： \n"<<endl;
    cout<< "--> ";
    string target;
    cin >> target;
    displaySingleInfo(stus,target);
}
void quitSys(vector<Student *>& stus){                                  // 清理內存
    vector<Student *>::iterator it;
    for(it = stus.begin();it != stus.end();it ++){
        delete (*it);
    }
}
Student* displaySingleInfo(vector<Student *>& stus,string target)       // 顯示單個學生信息
{
    Student *temp = __lookup(stus,target);
    if(temp != nullptr){
        cout << "\n學生姓名：" << temp->getName() << "  學號：" << temp->getID() << endl;
        cout<< "--scores:"<<endl;
        cout << "English: " << temp->getEng() << " Chinese: " << temp->getChi()
             << " Math: " << temp->getMat() << endl;
    }else{
        cout << "未查找到，請重試！" << endl; //TODO
        return nullptr;
    }
    return temp;
}
void displayAllInfos(vector<Student *>& stus){                          // 顯示總體信息
    int rank = 1;
    int len = static_cast<int>(stus.size());
    int sumEng = 0,sumChi = 0,sumMat = 0;
    sort(stus.begin(),stus.end(),comp);
    cout<< "\n\n\n------------------------------------------------------------\n";
    cout<< "                                             scores\n";
    cout<< "rank  "<<"Name          "<<"ID           "<<"English  "<<"Chinese  "<< "Math  "<<"Sum  \n";
    for(auto &stu : stus){
        cout.setf(ios::left);
        cout.width(6);  cout<<rank++;
        cout.width(14); cout<< stu->getName();
        cout.width(13); cout<< stu->getID();
        cout.width(9);  cout<< stu->getEng();
        cout.width(9);  cout<< stu->getChi();
        cout.width(6);  cout<< stu->getMat();
        cout<< stu->getsum()<<endl;
    }
    cout<< "\nsum                              ";
    cout.width(9); cout<<Student::engSum;
    cout.width(9); cout<<Student::chiSum;
    cout.width(6); cout<<Student::matSum<<endl;
    cout<< "average                          ";
    cout.width(9); cout<<Student::engSum/len;
    cout.width(9); cout<<Student::chiSum/len;
    cout.width(6); cout<<Student::matSum/len;
    cout<< "\n------------------------------------------------------------\n\n";
    cout<< "按下enter鍵以繼續" <<endl;
    getchar();
}
Student* __lookup(vector<Student *>& stus,string &target){
    vector<Student *>::iterator it;
    Student *ptr = nullptr;
    for(it = stus.begin();it != stus.end();it ++){
        if((*it)->getID() == target)
            ptr = (*it);
    }
    return ptr;
}
 

C++ 實現簡單命令行學生管理系統