BM24 二叉树的中序遍历

https://www.nowcoder.com/practice/0bf071c135e64ee2a027783b80bf781d?tpId=295&tqId=1512964&ru=/exam/oj&qru=/ta/format-top101/question-ranking&sourceUrl=%2Fexam%2Foj%3Fpage%3D1%26tab%3D%25E7%25AE%2597%25E6%25B3%2595%25E7%25AF%2587%26topicId%3D295

中序遍历，遍历顺序：左节点->当前节点->右节点

GO

切片slice模拟栈

package main

import . "nc_tools"

/*

* type TreeNode struct {

* Val int

* Left *TreeNode

* Right *TreeNode

* }

*/

/**

* 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整型一维数组

*/

func inorderTraversal( root *TreeNode ) []int {

// write code here

stack := make([]*TreeNode,0)

rc := root

result := make([]int,0)

for rc != nil || len(stack) > 0{

for rc != nil{

stack = append(stack,rc)

rc = rc.Left

}

rc = stack[len(stack)-1]

stack = stack[:len(stack)-1]

result = append(result, rc.Val)

rc = rc.Right

}

return result

}

 

运行时间 9ms

 

占用内存 1212KB

C++

 

/**

* struct TreeNode {

* int val;

* struct TreeNode *left;

* struct TreeNode *right;

* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}

* };

*/

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

vector<int> result;

stack<TreeNode*> st;

TreeNode* rc = root;

while(rc != nullptr || st.size() > 0){

while(rc != nullptr){

st.push(rc);

rc = rc->left;

}

rc = st.top();

st.pop();

result.push_back(rc->val);

rc = rc->right;

}

return result;

}

};

运行时间 4ms

 

占用内存 524KB