题解 | #二叉树的中序遍历#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 *	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
#include <vector>
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param root TreeNode类 
     * @return int整型vector
     */
    vector<int> inorderTraversal(TreeNode* root) {
        // write code here
        // 递归
        
        vector<int> res;
        if(root==nullptr){
            return res;
        }
        cout<<root->val<<endl;
        if(root->left!=nullptr){
            vector<int> resA = inorderTraversal(root->left);
            res.insert(res.end(), resA.begin(), resA.end());
        }
        res.push_back(root->val);
        if(root->right!=nullptr){
            vector<int> resB = inorderTraversal(root->right);
            res.insert(res.end(), resB.begin(), resB.end());
        }
        for(int i = 0; i<res.size(); i++) cout<<res[i];
        cout<<endl;
        return res;
    }


};