Need Help - Examination Timetable Generation

[aa85]

Hi all ,

I'm a senior IT student and I'm working now on my final IT project. I've been assigned by my university to develop a web-based system to generate final examination time table for them, didn't really have a choice. I've been told to use php to code my system and connect it to a MySQL database (which is not a problem for me as I've done a dynamic website using php and MySQL before). My problem, and I really hope that u'll help me out here, is how to write an algorithm for generating the time table using php T_T....

I tried to understand the idea of the algorithm from my supervisor and started to code using php. However, since I am not an expert in php programming, I faced problems in completing the code. Here is the code that I got till now, please I need ur comments and suggestions:

(The html form will contain: 1. Exam Period (in weeks) 2. starting date 3. ending date 4. program (BIT/BBA/Both))

 

<?php

extract($_POST);

 

//Connect to database and get list of subjects offered

 

if(!($database = mysql_connect("localhost", "timetable", "")))

die("Could not connect to database");

if(!mysql_select_db("CourseRegistration", $database))

die("Could not open Course Registration database");

$query = "Select * from Subjects";

if(!($subjects_array = array(mysql_query($query, $database)))){

print("Could not execute query! <br/>");

die(mysql_error());}

 

//Declare variables that will be needed

 

$no_of_days = 6*$weeks;

$total_students = 0;

$total_room_capacity = mysql_query("Select sum(capacity) from Halls", $database);

$TimeTableArray; //need it to be 2-dimensional

 

//Two loops (inner & outer) to generate the time table

 

for($rows = 0; $rows<$no_of_days; $rows++){

here I need to pick up the first subject in the array($subjects_array) and put it in the TimeTabelArray. Then delete the subject from the array, so that the program won't choose it again.

Make $total_students += student of the chosen subject.

 

for($cols = 0; $cols<5; $cols++){ //5 because only 5 halls are available, so max. 5 exams per day

here I need to pick up the next subject in the array($subjects_array), compare the students under this subject with the students of the previously chosen subject. If a student was found in both subjects, drop it and go back to the first for loop; otherwise, add the subject to the TimeTableArray, add the no. of students to the $total_students, and delete it from the $subjects_array.

 

if ($total_students < total_room_capacity/2) //coz two programs BIT & BBA so rooms should be divided equally between them.

continue in the same day (continue in the second loop)

 

else{

Use a method to rearrange the $subjects_array (to shift the still available subjects to the beginning of the array)

go to loop1}

 

}

}

 

//Assigning Halls

 

After the time table is generated, halls must be assigned to each exam (knapsack problem)...

 

 

//Assigning Chief Invigilators (all lecturers are assigned as chief invigilators)

 

This should be done using an array that will contain all the lecturers' names + the subjects they teach. Randomly assign each to an exam hall while checking that no lecturer assigned has one of his/her subjects' exam on that day.

?>

 

This is the whole idea of the code I need to write. Can anyone help me move step-by-step through it? I'd really appreciate any constructive modifications Very Happy

 

Thank u in advance