94.二叉树的中序遍历.cpp

/*
 * @lc app=leetcode.cn id=94 lang=cpp
 *
 * [94] 二叉树的中序遍历
 */
#include <iostream>
#include <string>
#include <vector>
using namespace std;
// @lc code=start
/**
 * 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 {
public:
    void inorder(TreeNode* root, vector<int> &result)
    {
        if(nullptr == root)
        {
            return;
        }
        inorder(root->left,result);
        result.push_back(root->val);
        inorder(root->right,result);
    }
    vector<int> inorderTraversal(TreeNode* root) {
        vector<int> result;
        inorder(root, result);
        return result;
    }
};
// @lc code=end