C + + linked list to achieve student performance management system (simple version)

That year C language class to write this is not written out, now have time, wrote a simple, slightly to make up for the regret has been.

#include <iostream> using namespace std;
    typedef struct student{int id;//number string sex;
    String name;
int cpp;//c++ score struct student *next;


}stu;

Stu *head=null; void Test (); Whether the test head pointer is an empty void record ();//records result void modify ();//modify result void print ();//print single score void aver ();//ask for the average score of each section void Count ();
    ID Add ();//Add student void Delt ();//delete student void print ();//print score int main () {int choice;
    cout<< "\t\t\t Student Achievement Management System \n\n\n";
    cout<< "0. Exit System 1. Record Information 2. Modify information 3. Average score 4. Statistical Results 5. Add Information 6. Delete Information 7. Print results \ n";
    cout<< "Input selection (0-7):";
    cin>>choice;
            while (1) {switch (choice) {case 0:exit (0);   Case 1:record ();
            Break   Case 2:modify ();
            Break   Case 3:aver ();
            Break   Case 4:count ();
            Break   Case 5:add ();
            Break   Case 6:delt ();
            Break   Case 7:print ();
           Break   default:cout<< "input error!\n";
    Break    } cout<< "Input selection (0-7):";
    cin>>choice;
return 0;
    	} void Test () {if (!head) {cout << head null\n;
    Exit (-1);
    } void Record () {Stu *p,*q;
    int i,n;
    cout<< "Enter the number of students:";
    cin>>n;
    i=0;
    cout<< "Input Student Information: Name learning number sex score \ n";
        while (i<n) {p=new stu;
            if (head==null) {head=p;
        Q=head;
            else {cin>>p->name>>p->id>>p->sex>>p->cpp;
            q->next=p;
            Q=p;
        i++;
    }} void Modify () {cout<< "Enter the student's number to modify:";
    int id;
    cin>>id;
    Stu *p;
    Test ();
    p=head->next;
            while (p) {if (p->id==id) {cout<< "Please select the content you want to modify: \ n";
            cout<< "1.id 2.name 3.sex 4.cpp\n";
            int choice;
            cin>>choice; Switch (choice)
            {Case 1: {int newid;
                    cout<< "Enter the newly learned number:";
                    cin>>newid;
                    p->id=newid;
                Break
                    Case 2: {string newname;
                    cout<< "Enter new name:";
                    cin>>newname;
                    p->name=newname;
                Break
                    Case 3: {string newsex;
                    cout<< "Enter the new sex:";
                    cin>>newsex;
                    p->sex=newsex;
                Break
                    Case 4: {int newcpp;
                    cout<< "Enter the new score:";
                    cin>>newcpp;
                    p->cpp=newcpp;
                Break default:cout<< "entered incorrectly!\n ";
            Break
        } break;
    } p=p->next;
    } void Aver () {Stu *p;
    int sum,i;
    sum=0;
    i=0;
    Test ();
    p=head->next;
        while (p) {sum+=p->cpp;
        i++;
    p=p->next;


cout<< "All classmates C + + 's average score is:" <<sum/i<<endl;}
    void Count () {int max;
    Stu *p,*q;
    Test ();
    p=head->next;
    max=p->cpp;
    Q=p;
        while (1) {p=p->next;
        if (p==null) break;
            if (max<p->cpp) {max=p->cpp;
        Q=p;


cout<<q->name<< "C + + got the first name \ n" << "highest divided into:" <<max<<endl;}
    void Add () {Stu *p,*q;
    P=new Stu;
    cout<< "Enter the name of the new addition classmate gender C + + results:";
    cin>>p->name>>p->id>>p->sex>>p->cpp;
    p->next=head->next;
head->next=p;
    } void Delt () {//system ("CLS");
    Stu *p,*q;
    int id; Cout<< "Enter the student's school number to delete:";
    cin>>id;
    Test ();
    Q=head;
    p=q->next;
            while (1) {if (p->id==id) {q->next=p->next;
            Delete p;
        Break
        } q=p;
    p=q->next;
    } void Print () {Stu *p;
    Test ();
    p=head->next;
        while (p) {cout<<p->name<< "" <<p->cpp<<endl;
    p=p->next; }
}