Scheduling algorithm for a round-robin tournament

The Problem We have a league with n players. every week they have a match with one other. in n-1 weeks every team fought against each other. there are n/2 matches a day. but one team can only fight once in a week. if we generate an (n/k) combination we get all of the combinations... (assuming k = 2) but i need to bring them in the right order.

The classic algorithm works like this:
Number the teams 1..n. (Here I'll take n=8.)
Write all the teams in two rows.

1 2 3 4
8 7 6 5

The columns show which teams will play in that round (1 vs 8, 2 vs 7, ...).
Now, keep 1 fixed, but rotate all the other teams. In week 2, you get

1 8 2 3
7 6 5 4

and in week 3, you get

1 7 8 2
6 5 4 3

This continues through week n-1, in this case,

1 3 4 5
2 8 7 6

If n is odd, do the same thing but add a dummy team. Whoever is matched against the dummy team gets a bye that week.


From: http://stackoverflow.com/questions/6648512/scheduling-algorithm-for-a-round-robin-tournament