// de bai: cho lop chung minh thu: dua tren lop chung minh thu xay dung // lop dan xuat sinh vien: // bao gom ham va phuong thuc sau: // lop cmt(so chung minh, ten chung minh, nam sinh // lop sinh vien ( ten lop, diem trung binh); // cac ham + phuong thuc: // ham tao khong doi, ham tao co doi; // ham huy, ham tao chep, phuong thuc toan tu gan; // phuong thuc toan tu xuat, nhap // phuong thuc lay dia chi cua lop chug minh thu // phuong thuc lay nam sinh // phuong thuc lay diem trung binh //ung dung: // cho lop k sinh vien viet chuong trinh in sinh vien co diem cao nhat va // in sinh vien co tuoi lon nhat: // bai lam: #include #include #include #include #include class cmt { char *scm, *hoten; int nam; public: cmt(); cmt( char*scm1,char*hoten1,int nam1); ~cmt(); cmt & operator=( cmt &); cmt(cmt &); cmt*laydc(); int laynam(); friend ostream & operator( istream & is, cmt & a); }; cmt::cmt() { scm= new char[9]; hoten= new char[25]; nam=0; }; cmt::cmt( char*scm1, char*hoten1, int nam1) { strcpy(scm,scm1); strcpy(hoten,hoten1); nam=nam1;}; cmt::~cmt() { delete scm; delete hoten; nam=0;}; cmt & cmt::operator=( cmt &a) { scm= new char[9]; hoten= new char[25]; strcpy(scm,a.scm); strcpy(hoten,a.hoten); nam=a.nam; return a; }; cmt::cmt( cmt & a) { (*this)=a;}; ostream & operator