1. The scores of the four people are 100,-100, 90, -90, and any match is enough, A44=24, (A44 is the combination number of 4).

2. The scores of four people are 100 and-100, and two people each get 100 and-100. Divide four people into two objects, C42C22 (you know,

24+ 12=36

In fact, this topic must be seriously considered, and it will be wrong if you don't pay attention. So, just sum up some mistakes, pay attention when doing the problem, and don't spend too much time on it. It's not necessary. Take a look at it when you are free.