# Weight based mapping algorithm

I am writing automatic assignment of tasks to the users. Every user has a weight (integer) and tasks should be distributed to the users according to their weights. For example I have 10 tasks and User A with weight 5, User B with weight 3 and User C with weight 2. Mapping function should assign User A with 5 task, B with 3 tasks, C with 2. This example is very straightforward, but it is not that easy when it comes to 34 users and 230 tasks for example. Is there any known algorithm i should look for?

• This is structurally the same problem as assigning seats in a parliamentary body to parties based on their number of votes. Search for "voting algorithms" to find solutions, or "voting paradoxes" if you want to be horrified. Jul 10, 2014 at 11:25

The algorithm seems simple enough, apart from rounding errors.

1. Add up all the weights => Wt.
2. Allocate each user a number of tasks = N times user weight Wx / Wt, rounded down.
3. There should be about N/2 task left over due to rounding. Allocate 1 task to each user in descending order of magnitude of rounding error (or any other algorithm if you prefer).