LeetCode 236. 【LCA】
原题链接
中等
作者:
大明湖的鱼
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2021-01-14 18:07:02
,
所有人可见
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阅读 299
多敲
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
if(root == nullptr) 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 != nullptr && right != nullptr) return root;//两个节点分别在左子树和右子树中
else if(left != nullptr) return left;
else if(right != nullptr) return right;
return nullptr;
}
};
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
if(root == NULL || p == root || q == root) return root;
TreeNode* left = lowestCommonAncestor(root->left,p,q);
TreeNode* right = lowestCommonAncestor(root->right,p,q);
if(left && right) return root;
return left?left:right;
}
};