树 Tree
- 二叉查找树 Binary search tree
参考： 《Thinking In Algorithm》06.Binary search tree（二叉查找树） - B 树 B Tree
参考：《Thinking In Algorithm》08.B-Tree - 红黑树 Red Black Tree
参考：《Thinking In Algorithm》07.Red-Black Trees（红黑树）
红黑树是二叉查找树的一种，满足二叉查找树的性质- The left subtree of a node contains only nodes with keys less than the node's key.
- The right subtree of a node contains only nodes with keys greater than the node's key.
- The left and right subtree each must also be a binary search tree.
- There must be no duplicate nodes.