#pragma once;
#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
using namespace std;
vector<Student>v;
class Student{
public:
    string name;
    float c_s;
    float cpp_s;
    float math_s;
    double sum;
    void caculateSum()
    {
        sum=c_s*0.3+cpp_s*0.4+math_s*0.3;
    }
};
void add_one_student(){
    Student s;
    cout<<"请依次输入姓名、C语言成绩、C++成绩、高数成绩"<<endl;
    cin>>s.name>>s.c_s>>s.cpp_s>>s.math_s;
    s.caculateSum();
    v.push_back(s);
}
void show_all_student(){
    for(int i=0;i<v.size();i++){
        cout<<v[i].name<<"\t"<<v[i].c_s<<"\t"<<v[i].cpp_s
            <<"\t"<<v[i].math_s<<"\t"<<v[i].sum<<endl;
    }
}
int main(){
    cout<<"欢迎使用班级成绩管理小程序\n";
    while(true){
        cout<<"\n【1】查看所有成绩\n【2】查看某一名学生成绩\n";
        cout<<"【3】修改某一名学生成绩\n【4】增加某一名学生成绩\n";
        cout<<"【5】删除某一名学生成绩\n【6】退出小程序\n";
            int select;
        Student s;
        cout<<"请输入您的选择:";
        cin>>select;
        switch(select){
            case 1:show_all_student();break;
            case 2:break;
            case 3:break;
            case 4:add_one_student();break;
            case 5:break;
            case 6:return 0;
            default:cout<<"对不起，您的输入有误!\n";break;
        }
    }
        return 0;
}

吃瓜群众随便问问：遇到同名的怎么办？

我也不知道，我还是个萌新