c++二叉树遍历

参考文献

数据结构c语言版，严蔚敏_吴伟民著。

二叉树

中序遍历代码实现

#include<vector>
#include<iostream>
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) {}
};class Solution {
public:vector<int> inorderTraversal(TreeNode* root) {vector<int> ans;if (root == nullptr) return ans;if (root->left != nullptr) {vector<int> ansLeft = inorderTraversal(root->left);     for (auto item : ansLeft) {ans.push_back(item);}}ans.push_back(root->val);if (root->right != nullptr) {vector<int> ansRight = inorderTraversal(root->right);for (auto item : ansRight) {ans.push_back(item);}}return ans;}
};int main()
{Solution s;TreeNode root(1);TreeNode node2(2);TreeNode node3(3);TreeNode node4(4);TreeNode node5(5);TreeNode node6(6);TreeNode node7(7);TreeNode node8(8);TreeNode node9(9);TreeNode node10(10);TreeNode node11(11);root.left = &node2;root.right = &node3;node2.left = &node4;node2.right = &node5;node3.left = &node6;node3.right = &node7;node5.left = &node8;node5.right = &node9;node9.left = &node10;node9.right = &node11;vector<int> ans = s.inorderTraversal(&root);for (auto item : ans) {cout << item << " ";}cout << endl;return 0;
}

结果