主观题：Tournament Trees

**Tournament tree** is a complete binary tree with $$n$$ external nodes and $$n-1$$ internal nodes. The external nodes represent the players and internal nodes represent the winner/loser of the match between the two players.

There are mainly two type of tournament tree:

* Winner tree: each node represents the winner. The final winner is represented by the root.
* Loser tree: The loser of the match is stored in internal nodes of the tree. But the overall winner of the tournament is stored at tree[0].

Tournament tree may be used in $$k$$-way merges.

What are the differences between winner and loser trees?  Which one would you prefer for $$k$$-way merge?  Why?





答案：