[LeetCode 236] 二叉树的最近公共祖先

本菜鸡能想到的方法MLE了
用例的树小的时候应该是可以过的，但就是因为俩vector导致MLE了QAQ

#include 
#include 
#include 

大佬的方法%%%

算是一时看懂了，主要在理解这行
return left == nullptr? right : (right == nullptr? left : root);
%%%%%%%

TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
        if(root == nullptr || root == p || root == q){return root; }
        TreeNode* left = lowestCommonAncestor(root->left, p, q);
        TreeNode* right = lowestCommonAncestor(root->right, p, q);
        return left == nullptr? right : (right == nullptr? left : root); //it's impossible that left and right are all nullptr
    }