Bai tap PASCAL

Program Cay_Nhi_Phan;
Uses Crt;
TYPE
Str = String[24];
ConTro = ^BanGhi;
BanGhi = RECORD
HoTen : Str;
Luong : Real;
Trai,Phai : ConTro;
End;
VAR
Goc : ConTro;
Nv : BanGhi;
Ketthuc : Boolean;
Ch : Char;
{--------------------------------}
Procedure Chen(Var Goc : ConTro; Nv : BanGhi);
Var
P,P1 : ConTro;
Begin
If goc = Nil Then
Begin
New(Goc);
With Goc^ Do
Begin
HoTen := NV.HoTen;
Luong := NV.Luong;
Trai := Nil;
Phai := Nil;
End;
End
Else
Begin
P := Goc;
P1 := Nil;
While P <> Nil Do
Begin
P1 := P;
If Nv.HoTen <= P^.HoTen Then
P := P^.Trai
Else
P := P^.Phai;
End;
New(P);
With P^ Do
Begin
HoTen := NV.HoTen;
Luong := NV.Luong;
Trai := Nil;
Phai := Nil;
End;
If NV.HoTen <=P1^.HoTen Then
P1^.Trai := P
Else
P1^.Phai := P;
End;
End;
{--------------------------------}
Procedure Xoa(Var Goc : ConTro; Nv : BanGhi);
Var
P,P1,Q,Q1 : ConTro;
Nhanh :(NhanhTrai,NhanhPhai);
Begin
If Goc = Nil Then
Writeln('Cay rong')
Else
Begin
P := Goc;
P1 := Nil;
While (P <> Nil) And (P^.HoTen <> Nv.HoTen) Do
Begin
P1 := P;
If Nv.HoTen < P^.HoTen Then
Begin
P := P^.Trai;
Nhanh := NhanhTrai;
End
Else
Begin
P := P^.Phai;
Nhanh := NhanhPhai;
End;
End;
If P = Nil Then
Writeln('Khong tim thay')
Else
Begin
If (P^.Trai = Nil) Then
Q := P^.Phai
Else
Begin
Q := P^.Trai;
Q1 := Nil;
While Q^.Phai <> Nil Do
Begin
Q1 := Q;
Q := Q^.Phai;
End;
If Q1 <> Nil Then
Begin
Q1^.Phai := Q^.Trai;
Q^.Trai := P^.Trai;
End;
If P1 = Nil Then
Goc := Q
Else
Begin
If Nhanh = NhanhTrai Then
P1^.Trai := Q
Else
P1^.Phai := Q;
End;
Dispose(P);
End;
End;
End;
End;
{--------------------------------}
Procedure Tim(Goc : ConTro; Nv : BanGhi);
Var
P : ConTro;
Begin
P := Goc;
While (P <> Nil) And (P^.HoTen <> Nv.HoTen) Do
If NV.HoTen < P^.HoTen Then
P := P^.Trai
Else
P := P^.Phai;
If P = Nil Then
Writeln('Khong tim thay')
Else
Begin
Writeln('Tim thay');
Writeln(P^.HoTen,' ', P^.Luong:8:1);
End;
End;
{--------------------------------}
Procedure LNRLietKe(Goc : ConTro);
Begin
If Goc = Nil Then
Begin
Writeln('Cay rong, chua co du lieu');
End
Else
Begin
If Goc^.Trai <> Nil Then
LNRLietKe(Goc^.Trai);
Writeln(Goc^.HoTen,', ',Goc^.Luong:8:1);
If Goc^.Phai <> Nil Then
LNRLietKe(Goc^.Phai);
End;
End;
{--------------------------------}
BEGIN
Repeat
ClrScr;
Writeln;
Writeln('CAC CHUC NANG CAY NHI PHAN');
Writeln('--------------------------');
Writeln;
Writeln('1-Khoi tao cay');
Writeln('2-Noi them vao cay');
Writeln('3-Xoa khoi cay');
Writeln('4-Tim kiem tren cay');
Writeln('5-Liet ke danh sach');
Writeln('6-Ket thuc chuong trinh');
Writeln;
Write('Chon cac chuc nang tu 1 den 6: ');
Readln(Ch);
Case Ch Of
'1' : Begin
ClrScr;
Writeln('1-KHOI TAO CAY');
Writeln('Cay co thu tu LNR');
Writeln('-----------------');
Writeln;
Goc := Nil;
KetThuc := False;
Repeat
With Nv Do
Begin
Write('-Ho ten hoac de ngung: ');
Readln(HoTen);
If HoTen <> '' Then
Begin
Write('-Bac luong : ');
Readln(Luong);
Chen(Goc,Nv);
End
Else
KetThuc := True;
End;
Until ketThuc;
End;
'2' : Begin
ClrScr;
Writeln;
Writeln('2-NOI VAO CAY THEO THU TU');
Writeln('-------------------------');
Writeln;
KetThuc := False;
Repeat
With Nv Do
Begin
Write('-Ho ten hoac de ngung: ');
Readln(HoTen);
If HoTen <> '' Then
Begin
Write('-Bac luong : ');
Readln(Luong);
Chen(Goc,Nv);
End
Else
KetThuc := True;
End;
Until ketThuc;
End;
'3' : Begin
ClrScr;
Writeln;
Writeln('3.XOA KHOI CAY');
Writeln('--------------');
Writeln;
KetThuc := False;
Repeat
With Nv Do
Begin
Write('Ho ten can xoa, hoac de ngung: ');
Readln(HoTen);
If HoTen <> '' Then
Xoa(Goc,NV)
Else
KetThuc := True;
End;
Until KetThuc;
End;
'4' : Begin
ClrScr;
Writeln('4-TIM KIEM TREN CAY');
Writeln('-------------------');
Writeln;
ketThuc := False;
Repeat
With Nv Do
Begin
Write('Ho ten can tim, hoac de ngung: ');
Readln(HoTen);
If HoTen <> '' Then
Tim(Goc,NV)
Else
KetThuc := True;
End;
Until KetThuc;
End;
'5' : Begin
ClrScr;
Writeln('5-LIET KE NOI DUNG CAY');
Writeln('Hien thi theo thu tu ABC...');
Writeln('---------------------------');
Writeln;
LNRLietKe(Goc);
Writeln;
Write('Xem xong bam . . . ');
Readln
End;
'6' : Begin
Writeln('7- KET THUC CHUONG TRINH');
Writeln;
End;
End;
Until Ch = '6'
END.