236.二叉树的最近公共祖先

😂递归

class Solution {
public:
    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
        if(!root || root == q || root == p)
            return root;
        TreeNode* left = lowestCommonAncestor(root->left, p, q);
        TreeNode* right = lowestCommonAncestor(root->right, p, q);
        if(left && right) 
            return root;
        if(left)
            return left;
        return right;
    }
};