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 p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself).”
root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 8
Explanation: The LCA of nodes 2 and 8 is 6.
root = [6,2,8,0,4,7,9,null,null,3,5], p = 2, q = 4
Explanation: The LCA of nodes 2 and 4 is 2, since a node can be a descendant of itself according to the LCA definition.
root = [2,1], p = 2, q = 1
- The number of nodes in the tree is in the range
-10^9 <= Node.val <= 10^9
p != q
qwill exist in the BST.
- 时间复杂度: O(n)
- 空间复杂度: O(h)
GitHub 代码同步地址： 235.LowestCommonAncestorOfABinarySearchTree.cpp