用C++语言找出二叉树最近公共祖先
用C++语言找出二叉树最近公共祖先
力扣题目：
解题思路：
如果二叉树为空，返回null；递归左右子树。
代码实现：
/**
* 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)
return NULL;
if(root == p || root == q)
return root;
//递归左右子树
TreeNode* left = lowestCommonAncestor(root->left, p, q);
TreeNode* right = lowestCommonAncestor(root->right, p, q);
if(left && right)
return root;
else if(left)
return left;
else if(right)
return right;
else
return NULL;
}
};
