LeetCode 538. 把二叉搜索树转换为累加树 中等

我的解题

#include <bits/stdc++.h>
using namespace std;

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */

struct TreeNode
{
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() :
                    val(0), left(nullptr), right(nullptr)
    {
    }
    TreeNode(int x) :
                    val(x), left(nullptr), right(nullptr)
    {
    }
    TreeNode(int x, TreeNode *left, TreeNode *right) :
                    val(x), left(left), right(right)
    {
    }
};
class Solution
{
    int sum { 0 };
public:
    TreeNode* convertBST(TreeNode *root)
    {
        traverse(root);
        return root;
    }
    void traverse(TreeNode *root)
    {
        if (root)
        {
            traverse(root->right);
            sum += root->val;
            root->val = sum;
            traverse(root->left);
        }
    }
};

int main()
{

}
// g++ test.cpp --std=c++11 -pedantic -Wall -Wextra