You are to create a system that will record the marks in CS1 for each student in each division at ADFA.
The following items are required
------------------------------------------------------------------------------
-- Program: main.a
-- Author: Chist Lokan
-- Modified: Xin Yao, 10 August 1997
-- Program Purpose: Maintain a database of CS1 marks for ADFA students.
------------------------------------------------------------------------------
with TEXT_IO;
procedure main is
-- declare integer I/O library
package int_io is new TEXT_IO.INTEGER_IO(INTEGER);
use TEXT_IO,int_io;
-- declare contants
max_rank_size: constant:=3; -- max str length for ranks
max_sname_size: constant:=20; -- max str length of a name
max_phone_len: constant:=10; -- max str length of tel no
max_div_students: constant:=30; -- max no of students in a div
space: constant CHARACTER := ' '; -- blank space
-- declare various types and subtypes
subtype ranks is STRING(1..max_rank_size);
subtype snames is STRING(1..max_sname_size);
subtype phones is STRING(1..max_phone_len);
type sexes is (male, female);
subtype years is INTEGER range 1..10;
subtype results is INTEGER range 1..100;
-- declare and initialise a record type for a student's detail (rank and name)
type details is record
rank: ranks:= (others=> space); -- rank
sname: snames:= (others=> space); -- surname
end record;
-- a record type including all information about a student
type students is record
detail: details; -- rank and name
phone : phones := (others => space); -- phone no
sex : sexes; -- sex
year : years:=1; -- year, initialised to 1
result: results:=1; -- mark, initialised to 1
end record;
-- an array type describing a division of students
type divresults is array(1..max_div_students) of students;
-- an array type describing a number of divisions (unconstrained array)
type adfaresults is array(INTEGER RANGE <>) of divresults;
-- deckare an I/O library for the new type sexes
package sex_io is new TEXT_IO.ENUMERATION_IO (sexes);
use sex_io;
-- declare global variables
adfaresult : adfaresults(1..6); -- ADFA has 6 divs
c : character; -- a character for reading
div, -- division at ADFA
pos : integer; -- position no
surname : snames:= (others=> space); -- surname of a student
student : students; -- student info (a record)
nchar : natural; -- length of an input string
--------------------------------------------------------------------------
-- Function: getstudent
-- Purpose: read in all the info about a student and return a record
-- contain those info
--------------------------------------------------------------------------
function getstudent return students is
student: students; -- a student record
nchar: natural; -- string length, for GET_LINE
begin -- getstudent
student.detail.rank:=(others=>space); -- initialise rank to blanks
PUT("Enter rank: ");
GET_LINE(student.detail.rank,nchar); -- get rank
student.detail.sname:=(others=>space); -- initialise name to blanks
PUT("Enter surname: ");
GET_LINE(student.detail.sname,nchar); -- get surname
student.phone:=(others=>space); -- initialise phone no to blanks
PUT("Enter phone: ");
GET_LINE(student.phone,nchar); -- get phone umber
PUT("Enter sex: ");
GET(student.sex); SKIP_LINE; -- get sex
PUT("Enter year: ");
GET(student.year); SKIP_LINE; -- get year
PUT("Enter result: ");
GET(student.result); SKIP_LINE; -- get mark (result)
return student;
end getstudent;
----------------------------------------------------------------------------
-- Function: findstudent
-- Purpose: find a student with a particular surname in the adfa database
----------------------------------------------------------------------------
function findstudent(adfa: adfaresults; -- the student database
findname: snames -- surname to be found
) return students is -- the student record found
empty: students; -- a local variable to hold a student record
begin -- findstudent
for division in adfa'RANGE loop -- for all the divs at ADFA
for student in divresults'RANGE loop -- for all students in a div
if adfa(division)(student).detail.sname = findname then
return adfa(division)(student); -- found the student
end if;
end loop;
end loop;
return empty; -- student not found
end findstudent;
----------------------------------------------------------------------------
-- Function: averagediv
-- Purpose: calculate the average mark of students in a div
----------------------------------------------------------------------------
function averagediv(div: divresults) return INTEGER is
total: integer:=0; -- average mark in a div
currstud: integer:=1; -- index of the array
begin -- averagediv
while ((div(currstud).detail.sname /= " ")
and (currstud<max_div_students)) loop
total := total + div(currstud).result;
currstud := currstud + 1;
end loop;
if (currstud-1) = 0 then -- if no records found, return -1
return -1;
end if;
return total/(currstud-1); -- return the average mark as an integer
end averagediv;
begin -- main
loop
-- display the menu
put_line("What do you want to do");
put_line("1) Add record");
put_line("2) Find record");
put_line("3) Print averages");
put_line("4) Quit");
get(c); SKIP_LINE; -- read in the menu choice
case (c) is
when '1' => -- add a student record
put("What div? "); -- student's div
get(div); SKIP_LINE;
put("What position? "); -- student's sequential position in the div
get(pos); SKIP_LINE;
adfaresult(div)(pos):= getstudent; -- read in the student info
when '2' => -- find a student record
put("What surname? ");
get_line(surname, nchar); -- read in the surname
student := findstudent (adfaresult,surname); -- find the student
put(student.result); -- display his/her mark/result
NEW_LINE;
when '3' => -- print averages for all divisions
put_line ("Division Average Mark"); -- table heading
for division in adfaresult'RANGE loop
put (division, width=>4); -- display the division number
put (averagediv(adfaresult(divsision)), width=>14);
-- dislpay the average
NEW_LINE;
end loop;
when others => exit;
end case;
end loop;
end main;