题目描述:
给定一个二叉树, 找到该树中两个指定节点的最近公共祖先。
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
if(root==null)
return root;
if(root==p || root==q)
return root;
TreeNode left = lowestCommonAncestor(root.left,p,q);
TreeNode right = lowestCommonAncestor(root.right,p,q);
if(left!=null && right!=null)
return root;
if(left!=null)
return left;
if(right!=null)
return right;
return null;
}
}