building a weekly roster application in java
Page 1 of 17 Replies  2586 Views  Last Post: 15 January 2009  10:45 AM
#1
building a weekly roster application in java
Posted 15 January 2009  07:27 AM
I am not asking to give me code or something but i need some ideas on how shall i do this.
i am thinking as inputting the availability for each worker and then buildthe roster from the availabilities. i am not sure how the logic of the programm should be so i am trying to get help.
thanks
Replies To: building a weekly roster application in java
#2
Re: building a weekly roster application in java
Posted 15 January 2009  08:47 AM
It's like, you want every timeslot to be covered by k workers while one worker can only work for t hours per week and he cannot work in adjacent time slots, something like that?
Start by writing down the constraints, here as well so we know what we have to work with, maybe we can help you with ideas.
#3
Re: building a weekly roster application in java
Posted 15 January 2009  09:01 AM
Gloin, on 15 Jan, 2009  07:47 AM, said:
It's like, you want every timeslot to be covered by k workers while one worker can only work for t hours per week and he cannot work in adjacent time slots, something like that?
Start by writing down the constraints, here as well so we know what we have to work with, maybe we can help you with ideas.
yes something like that, there are 2 shifts in every day morning and evening, in every shift there have to be k workers. every worker must atleast be given 4 shifts and the rest are spread randomly.
i dont know exactly the algorithm that i need to use inorder to fill the slots. i dont know exactly were to start from, and what do i need exactl in my hand. maby if i have this idea cleared i can run with my code then.
#4
Re: building a weekly roster application in java
Posted 15 January 2009  09:40 AM
Let every shift be represented be a vertex and let an edge between two vertex represent that they would 'overlap'.
The way to solve the problem can depend on the resources.
1* Is any worker available for any timeslot?
2* Can one worker work any number of shifts (max: number of shifts / 2)
3* If there are k workers, are there more than 4*k shifts? (If not the problem can't be solved)
If you calculate the number of shifts divided by the number of workers, you can simple round the number down and start filling every shift with that many workers until every shift has equally many workers this way you won't get overlaps. Th remaining workers can be scattered among the shifts. Just see if a worker can work shift i (not working shift i1 or i+1), if he can't you try with the next worker.
This is a greedy algorithm, it may not be optimal.
#5
Re: building a weekly roster application in java
Posted 15 January 2009  09:55 AM
Gloin, on 15 Jan, 2009  08:40 AM, said:
Let every shift be represented be a vertex and let an edge between two vertex represent that they would 'overlap'.
The way to solve the problem can depend on the resources.
1* Is any worker available for any timeslot?
2* Can one worker work any number of shifts (max: number of shifts / 2)
3* If there are k workers, are there more than 4*k shifts? (If not the problem can't be solved)
If you calculate the number of shifts divided by the number of workers, you can simple round the number down and start filling every shift with that many workers until every shift has equally many workers this way you won't get overlaps. Th remaining workers can be scattered among the shifts. Just see if a worker can work shift i (not working shift i1 or i+1), if he can't you try with the next worker.
This is a greedy algorithm, it may not be optimal.
there are 14 shift in every week, 2 for everyday. i dont have the restriction as such just given this task to do, so i can make the restriction favourable for me to make it easy to code.
i am a beginer in java and dont know exactly how to work with vertex.
#6
Re: building a weekly roster application in java
Posted 15 January 2009  10:05 AM
If you have k workers, let half of them work the first shift, the other half works the second shift, first half works the third shift and so on.
If there are no restrictions you might as well make it easy on yourself.
or, if it has to be exactly k workers in a shift..
first k workers work the first shift, next k workers take the next shift, next k take the third and if you run out of workers you start over from the first worker. (Use modulo operation here)
This post has been edited by Gloin: 15 January 2009  10:09 AM
#7
Re: building a weekly roster application in java
Posted 15 January 2009  10:20 AM
Gloin, on 15 Jan, 2009  09:05 AM, said:
If you have k workers, let half of them work the first shift, the other half works the second shift, first half works the third shift and so on.
If there are no restrictions you might as well make it easy on yourself.
or, if it has to be exactly k workers in a shift..
first k workers work the first shift, next k workers take the next shift, next k take the third and if you run out of workers you start over from the first worker. (Use modulo operation here)
can u give me an example on how CAn i begin the code?
#8
Re: building a weekly roster application in java
Posted 15 January 2009  10:45 AM
Let there be m workers (ex, m = 8), every worker is represented by a number between 0 and m1
So we got workers 0, 1, 2, 3, 4, 5, 6 & 7
Next, you have the roster which is represented by a 2dimensional (int) array with 14 * k elements because you have 14 timeslots and every timeslot needs k workers. Call the array Roster[14][k]. (for the example, let k=3, I.e 3 workers per timeslot.
In Roster[0][0] you put worker 0.
In Roster[0][1] you put worker 1.
In Roster[0][2] you put worker 2.
Now you covered the first timeslot.. You continue with..
In Roster[1][0] you put worker 3.
In Roster[1][1] you put worker 4.
In Roster[1][2] you put worker 5.
Then
In Roster[2][0] you put worker 6.
In Roster[2][1] you put worker 7.
You just ran out of workers so you start over from 0 but instead of using ifstatements and crap like that..
In Roster[2][2] you put worker (8%m). m=8 so 8%8 = 0, this is what you wanted.
Then
In Roster[3][0] you put worker (9%m). 9%8 = 1
In Roster[3][1] you put worker (10%m). 10%8 = 2
In Roster[3][2] you put worker (11%m). 11%8 = Well have a guess.
And so on..
You can find a mathematical formula to assign every position in the array using just one line of code inside a forloop.
for (int i = 0; i < 14*k; i++) Roster[i / k][i % k] = i % m;
It's magic!
This post has been edited by Gloin: 15 January 2009  10:47 AM
