Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.
According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v and w as descendants (where we allow a node to be a descendant of itself).”
_______6______
/
___2__ ___8__
/ /
0 _4 7 9
/
3 5
For example, the lowest common ancestor (LCA) of nodes 2 and 8 is 6. Another example is LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.
题目含义：给定一棵二叉树，寻找其中两个给定节点的最近公共祖先（LCA）。
1 public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) { 2 while (true) 3 { 4 if (root.val > Math.max(p.val,q.val)) root = root.left; 5 else if (root.val < Math.min(p.val,q.val)) root = root.right; 6 else break; 7 } 8 return root; 9 }