search in multilevel linked lists in Pascal - data-structures

Question

So in this program we are asked to create a database for a university, the university is divided into faculties and each faculty is divided into departments, similarly, each department is divided into courses (specialities) and each course is divided into grades, and each grade has a list of students. I implemented this using linked lists, after the user fills the database, they get some options to interact with the database such as adding and removing students, etc. But, when I try to search for a student in the database it seems not to search well although the method works well when searching for a course (it gives in which faculty the course is and in which department). When the program is executed it gives us the message ("name" doesn't exist in this database) which indicates that cmp is still set to 0.
Program Liked_lists_database;
Type
Node = ^T;
T = record
age : string;
next, link : Node;
end;
Var
Head, Tail, Last, tmp, tmp2, tmp3, tmp4, tmp5 : Node;
y : string;
cmp : integer;
Begin
writeln('[+] Create your database [+]');
writeln;
Repeat
write('Enter the name of the faculty : ');
readln(j);
if (j='exit') then break;
if (Head = nil) then
Begin
new(Head);
Tail := Head;
End
Else
Begin
new(Tail^.next);
Tail := Tail^.next;
End;
Tail^.age := j;
Tail^.next := nil;
Repeat
Write('Enter the name of the department : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link=Nil) Then
Begin
new(Tail^.link);
Last := Tail^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the name of the course : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link=Nil) Then
Begin
new(Tail^.link^.link);
Last := Tail^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the grade : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link^.link=Nil) Then
Begin
new(Tail^.link^.link^.link);
Last := Tail^.link^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the name of the student : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link^.link^.link=Nil) Then
Begin
new(Tail^.link^.link^.link^.link);
Last := Tail^.link^.link^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Until false;
Until false;
Until false;
Until false;
Until false;
writeln;
writeln('...The database has been created successfully!');
// Search for a student
writeln('[+] Search for a student');
write('Enter the name of the student to Search for : ');
readln(y);
tmp := Head;
cmp := 0;
if (cmp=0) then
While (tmp^.next<>Nil) Do
Begin
tmp2 := tmp^.link;
While (tmp2^.next<>Nil) Do
Begin
tmp3 := tmp2^.link;
While (tmp3^.next<>Nil) Do
Begin
tmp4 := tmp3^.link;
While (tmp4^.next<>Nil) Do
Begin
tmp5 := tmp4^.link;
While (tmp5^.next<>Nil) Do
Begin
if (tmp5^.age=y) then
cmp := cmp + 1;
tmp5 := tmp5^.next;
End;
if (cmp>0) then
tmp4^.next := Nil
Else
tmp4 := tmp4^.next;
End;
if (cmp>0) then
tmp3^.next := Nil
Else
tmp3 := tmp3^.next;
End;
if (cmp>0) then
tmp2^.next := Nil
Else
tmp2 := tmp2^.next;
End;
if (cmp>0) then
tmp^.next := Nil
Else
tmp := tmp^.next;
End;
if (cmp>0) then
Begin
writeln('Name : ',y);
writeln('Faculty : ', tmp^.age);
writeln('Department : ', tmp2^.age);
writeln('Speciality : ', tmp3^.age);
writeln('Grade : ', tmp4^.age);
End
Else
writeln(y, ' does not exist in this database');
End.
EDIT : the problem was with the implementation of the multilevel linked list and the searching algorithm
Program Liked_lists_database;
Type
Node = ^T;
T = record
age : string;
next, link : Node;
end;
Var
Head, Tail, tmp, Last : Node;
j: string;
num : integer;
Procedure searchCourse;
Var
cmp : integer;
y : string;
tmp, tmp2, tmp3 : Node;
Begin
writeln('[+] Search for a course');
write('Enter the name of the course to Search for : ');
readln(y);
tmp := Head;
cmp := 0;
if (tmp^.next=Nil) Then
new(tmp^.next);
While (tmp^.next<>Nil) Do
Begin
tmp2 := tmp^.link;
if (tmp2^.next=Nil) Then
new(tmp2^.next);
While (tmp2^.next<>Nil) Do
Begin
tmp3 := tmp2^.link;
While (tmp3<>Nil) Do
Begin
if (tmp3^.age=y) Then
Begin
writeln('[', y, '] is found in faculty of [ ', tmp^.age, ']', ' department of [', tmp2^.age, ']');
cmp := 1;
End;
tmp3 := tmp3^.next;
End;
if (cmp=0) Then
Begin
tmp2 := tmp2^.next;
if (tmp2^.next=Nil) Then
new(tmp2^.next);
End
Else
tmp2^.next := Nil;
End;
if (cmp=0) Then
Begin
tmp := tmp^.next;
if (tmp^.next=Nil) Then
new(tmp^.next);
End
Else
tmp^.next := Nil;
End;
if (cmp=0) Then
writeln ('[', y, '] : there is no such course');
End;
Begin
// Fillin in the database
writeln('[+] Create your database [+]');
writeln;
Repeat
write('Enter the name of the faculty : ');
readln(j);
if (j='exit') then break;
if (Head = nil) then
Begin
new(Head);
Tail := Head;
End
Else
Begin
new(Tail^.next);
Tail := Tail^.next;
End;
Tail^.age := j;
Tail^.next := nil;
Repeat
Write('Enter the name of the department : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link=Nil) Then
Begin
new(Tail^.link);
Last := Tail^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the name of the course : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link=Nil) Then
Begin
new(Tail^.link^.link);
Last := Tail^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the grade : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link^.link=Nil) Then
Begin
new(Tail^.link^.link^.link);
Last := Tail^.link^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Repeat
Write('Enter the name of the student : ');
Readln(j);
if (j='exit') then break;
if (Tail^.link^.link^.link^.link=Nil) Then
Begin
new(Tail^.link^.link^.link^.link);
Last := Tail^.link^.link^.link^.link;
End
Else
Begin
new(Last^.next);
Last := Last^.next;
End;
Last^.age := j;
Last^.next := Nil;
Until false;
Until false;
Until false;
Until false;
Until false;
writeln;
writeln('...The database has been created successfully!');
searchCourse;
Readln;
End.