无法解析外部命令问题

Question

不知道为什么
不懂怎么解决

#include<iostream>
#include<vector>
using namespace std;

//学生类
class student
{
public:
    string name;
    string numbering;
    int score;
    student(string m_name = 0, string m_numbering = 0, int m_score = 0)
    {
        this->name = m_name;
        this->numbering = m_numbering;
        this->score = m_score;
    }
};

//建立容器
void Vector(student &stu)
{
    vector<student>s;
    s.push_back(stu);
}

//增加学生
void addStudent()
{
    cout << "请输入学生名字：";
    string Name;
    cin >> Name;
    cout << "请输入学生学号：";
    string id;
    cin >> id;
    cout << "请输入学生分数：";
    int Score;
    cin >> Score;
    student stu(Name, id, Score);
    Vector(stu);
}


int mian()
{
    cout << "#######################" << endl;
    cout << "##### 1、增加学生 #####" << endl;
    cout << "##### 2、删除学生 #####" << endl;
    cout << "##### 3、显示学生 #####" << endl;
    cout << "##### 4、查找学生 #####" << endl;
    cout << "##### 5、学生排名 #####" << endl;
    cout << "##### 6、退出系统 #####" << endl;
    cout << "#######################" << endl;
    cout << "请输入您的选择" << endl;
    int select;
    cin >> select;
    switch (select)
    {
    case 1:
        addStudent();
        break;
    case 2:
        break;
    case 3:
        break;
    case 4:
        break;
    case 5:
        break;
    case 6:
        system("pause");
        system("cls");
        return 0;
        break;
    default:
        system("pause");
        system("cls");
        return 0;
        break;
    }

    return 0;
}

该怎么解决，怎么修改才能跑起来

Answer 1

int main()
不是int mian()