How many football matches are there in Java? List operations.

Obviously, take the World Cup group match as an example. There are four teams and six games.

This is the combinatorial knowledge of mathematics. It is equivalent to choosing two teams from four teams to play.

Similarly, two teams were selected from 14, and the match * * * was 9 1.

There is a slight problem with the topic.

Simply put, the formula is14 *13/2 = 91.