java data structure - red-black trees (RB Tree)

Compared to red-black tree balanced binary tree (AVL) is a weak balanced tree, and has the following characteristics:

1, each node in the non-red or black;

2, the root node is black;

3, each leaf node (i.e., a leaf node tree or NULL NULL pointer tail node) is black;

4. As shown, if a node is red, then its two sons are black;

5, for any node, each path which points to a leaf of the tree NULL pointer contains the same number of black nodes;

6, each path comprising nodes same black