求助急看了一下午也找不到错误

#include<iostream.h>
#include<string.h>
class people
{
protected:
    int age;
    char name[20];
public:
    people(char *n,int a):age(a)
    {
        strcpy(name,n);
    }
    void print()
    {
        cout<<"The name of the people is:"<<name<<endl<<"The age of the people is:"<<age<<endl<<endl;
    }
};
class student:public virtual people
{
protected:
    char classno[7];
public:
    student(char *n,int a,char *c):people(n,a)
    {
        strcpy(classno,c);
    }
    void print()
    {
        cout<<"The name of the student is :"<<name<<endl<<"The age of the student is:"<<age<<endl;
        cout<<"The classno of the student is :"<<classno<<endl<<endl;
    }
};
class techer:public virtual people
{
protected:
    char principalship[11];
    char department[21];
public:
    techer(char *n,int a,char *p,char *d):people(n,a)
    {
        strcpy(principalship,p);
        strcpy(department,d);
    }
    void print()
    {
        cout<<"The name of the techer is :"<<name<<endl<<"The age of the techer is:"<<age<<endl;
        cout<<"The principalship of the techer is:"<<principalship<<endl;
        cout<<"The deparcipalship of the thcher is:"<<department<<endl<<endl;
    }
};
class graduate:virtual public student
{
protected:
    char subject[21];
    techer adviser;
public:
    graduate(char *n,int a,char *c,char *s,techer t):people(n,a),student(n,a,c),adviser(t)
    {
        strcpy(subject,s);
    }
    void print()
    {
        cout<<"The name of the graduate is:"<<name<<endl<<"The age of the gratuate is:"<<age<<endl;
        cout<<"The calssno of the graduate is:"<<classno<<endl;
        cout<<"The subject of the graduate is:"<<subject<<endl;
        cout<<"The techer adviser of the graduate is:";
        adviser.print();
    }
};
class TA: public graduate, public techer
{
public:
    TA(char *n,int a,char *s,techer t,char *p,char *d,char *c):people(n,a),student(n,a,c),techer(n,a,p,d),graduate(n,a,c,s,t){}
    void print()
    {
        cout<<"The name of the TA is:"<<name<<endl<<"The age of TA is:"<<age<<endl;
        cout<<"The calssno of the TA is:"<<classno<<endl;
        cout<<"The subject of the TA is:"<<subject<<endl;
        cout<<"The techer adviser of the TA is:";
        adviser.print();
        cout<<"The principalship of the techer is:"<<principalship<<endl;
        cout<<"The deparcipalship of the thcher is:"<<department<<endl<<endl<<endl;
    }
};
void main()
{
    char n[20],int a;char classnumber[10];char department[21];
    char principalship[11];char subject[10];
    cout<<"输入姓名："<<endl;
    cin>>n;
    cout<<"输入年龄："<<endl;
    cin>>a;
    people f(n,a);
    f.print();
    cout<<"输入学生姓名："<<endl;
    cin>>n;
    cout<<"输入学生年龄："<<endl;
    cin>>a;
    cout<<"输入学生班级："<<endl;
    cin>>classnumber;
    student b(n,a,classnumber);
    b.print();
    cout<<"输入姓名："<<endl;
    cin>>n;
    cout<<"输入教师年龄："<<endl;
    cin>>a;
    cout<<"输入教师职务:"<<endl;
    cin>>principalship;
    cout<<"输入教师部门"<<endl;
    cin>>department;
    techer c(n,a,principalship,department);
    c.print();
    cout<<"输入研究生姓名："<<endl;
    cin>>n;
    cout<<"输入研究生年龄："<<endl;
    cin>>a;
    cout<<"输入学生班级："<<endl;
    cin>>classnumber;
    cout<<"研究生专业"<<endl;
    cin>>subject;
    graduate d(n,a,classnumber,subject,c);
    d.print();
    cout<<"输入助教姓名："<<endl;
    cin>>n;
    cout<<"输入助教年龄："<<endl;
    cin>>a;
    cout<<"输入助教班级："<<endl;
    cin>>classnumber;
    cout<<"助教专业"<<endl;
    cin>>subject;
    TA e(n,a,subject,c,principalship,department,classnumber);
    e.print();

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