https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ 这里是BT不是BST,思路就是找到root到p和q的path然后找到最后的一个交点。要注意如何find Path。 如何用递归 http://bookshadow.com/weblog/2015/07/13/leetcode-lowest-common-ancestor-binary-tree/ 思路1 findPath。。。用post-orde...
如果某一node在它的左右子树里面分别返回了两个不为null的点, 则说明左边也找到一点啥,右边也找到一点啥,最低公共祖先肯定 是这个了。 publicTreeNodelowestCommonAncestor(TreeNode root,TreeNode p,TreeNode q){if(root==null)returnnull;if(root==p||root==q)returnroot;TreeNode left=lowestCommonAncestor(r...
* @param A: A TreeNode in a Binary. * @param B: A TreeNode in a Binary. * @return: Return the least common ancestor(LCA) of the two nodes.*/TreeNode* lowestCommonAncestor(TreeNode * root, TreeNode * A, TreeNode *B) {//write your code hereif(root==NULL) {returnroot; } ve...
TreeNode q){if(root==null){returnnull;}if(root==p||root==q){returnroot;}TreeNode left=lowestCommonAncestor(root.left,p,q);TreeNode right=lowestCommonAncestor(root.right,p,q);if(left!=null&&right!=null){returnroot;}if(left!=null){returnleft;}if(right!=null){returnright;}returnnull...
http://www.geeksforgeeks.org/lowest-common-ancestor-binary-tree-set-1/ 1 #include 2 #include 3 #include 4 #include 5 #include 6 #include 7 #include 8
Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. 百度百科中最近公共祖先的定义为:“对于有根树 T 的两个结点 p、q,最近公共祖先表示为一个结点 x,满足 x 是 p、q 的祖先且 x 的深度尽可能大(一个节点也可以是它自己的祖先)。” ...
public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) { if (root == null) { return root; } if (root.val > Math.max(p.val, q.val)) { return lowestCommonAncestor(root.left, p, q); } else if (root.val < Math.min(p.val, q.val)) { ...
简介:根据LCA的定义,二叉树中最小公共祖先就是两个节点p和q最近的共同祖先节点,LCA的定义没什么好解释的,主要是这道题的解法。 题目链接 236. Lowest Common Ancestor of a Binary Tree 根据LCA的定义,二叉树中最小公共祖先就是两个节点p和q最近的共同祖先节点,LCA的定义没什么好解释的,主要是这道题的解法。
7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) { //这是一棵排序树啊! 13 if( (root->val - p->val ) * (root->val - q->val) <=0...
Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to thedefinition 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 (wh...