Red-Black Property 我们为什么需要红黑树这么一种特别的数据结构？ 1.Every node is either red or black. 2.The root is black. 3.Every leaf (NIL)is black. 4.If a node is red,then both its children are black. 5.For each node,all simple paths from the node to descendant leaves contain the same number of black nodes.Red-Black Property 我们为什么需要红黑树这么一种特别的数据结构？