LeetCode：1123. Lowest Common Ancestor of Deepest Leaves

又一次给评论区的大神跪了。
首先我自己的解法：

class Solution {
public:
    TreeNode* lcaDeepestLeaves(TreeNode* root) {
        vector<TreeNode*> tempPath, maxDepthPath;
        int maxDepth = 0;
        helper(root, 0, maxDepth, tempPath, maxDepthPath);
        return maxDepthPath.empty()? nullptr : maxDepthPath.back();
    }
private:
    void helper(TreeNode* node, int depth, int& maxDepth, vector<TreeNode*>& tempPath, vector<TreeNode*>& maxDepthPath) {
        if (!node) 
            return;
        ++depth;
        tempPath.push_back(node);
        if (!node->left && !node->right) {
            if (depth < maxDepth) {
                tempPath.pop_back();
                return;
            }
            if (depth > maxDepth) {
                maxDepthPath = tempPath;
                maxDepth = depth;
            }
            if (depth == maxDepth) {
                handle(maxDepthPath, tempPath);
            }
        } 
        if (node->left)
            helper(node->left, depth, maxDepth, tempPath, maxDepthPath);
        if (node->right)
            helper(node->right, depth, maxDepth, tempPath, maxDepthPath);
        tempPath.pop_back();
    }
    
    void handle(vector<TreeNode*>& maxDepthPath, vector<TreeNode*>& tempPath) {
        if (maxDepthPath.empty()) {
            maxDepthPath = tempPath;
            return;
        }
        int i = 0;
        for (; i < maxDepthPath.size(); ++i) {
            if (maxDepthPath[i] != tempPath[i])
                break;
        }
        for (int j = maxDepthPath.size()-1; j >= i; --j)
            maxDepthPath.pop_back();
    }
};

又长又臭。
来看看评论区的解法：

class Solution {
public:
    TreeNode* lcaDeepestLeaves(TreeNode* root) {
        return helper(root).first;
    }
private:
    pair<TreeNode*, int> helper(TreeNode* node) {
        if (!node)
            return make_pair(nullptr, 0);
        auto lp = helper(node->left);
        auto rp = helper(node->right);
        if (lp.second > rp.second)
            return make_pair(lp.first, lp.second+1);
        if (lp.second < rp.second)
            return make_pair(rp.first, rp.second+1);
        return make_pair(node, lp.second+1);
    }
};

简洁优雅。
我能说什么呢（真是个辣鸡