108.Convert Sorted Array to Binary Search Tree(Array; Divide-and-Conquer, dfs)
Given an array where elements are sorted in ascending order, convert it to a height balanced BST.
思路:使用二分法,将list的中间节点作为根节点,然后分别处理list左半边及右半边,以此递归。
struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
class Solution {
public:
TreeNode *sortedArrayToBST(vector<int> &num) {
if(num.empty()) return NULL;
TreeNode* root = new TreeNode();
dfs(num,,num.size()-,root);
return root;
}
void dfs(vector<int> &num,int start, int end,TreeNode* treeNode)
{
int size = end-start+;
if(size == )
{
treeNode->val = num[start];
return;
}
int mid = size/ + start;
treeNode->val = num[mid];
treeNode->left = new TreeNode();
dfs(num,start,mid-,treeNode->left);
if(mid+<=end)
{
treeNode->right = new TreeNode();
dfs(num,mid+,end,treeNode->right);
}
}
};
108.Convert Sorted Array to Binary Search Tree(Array; Divide-and-Conquer, dfs)的更多相关文章
- 108. Convert Sorted Array to Binary Search Tree 109. Convert Sorted List to Binary Search Tree -- 将有序数组或有序链表转成平衡二叉排序树
108. Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascendin ...
- leetcode 108. Convert Sorted Array to Binary Search Tree 、109. Convert Sorted List to Binary Search Tree
108. Convert Sorted Array to Binary Search Tree 这个题使用二分查找,主要要注意边界条件. 如果left > right,就返回NULL.每次更新的 ...
- [Leetcode][JAVA] Convert Sorted Array to Binary Search Tree && Convert Sorted List to Binary Search Tree
Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in ascending ord ...
- 34. Convert Sorted List to Binary Search Tree && Convert Sorted Array to Binary Search Tree
Convert Sorted List to Binary Search Tree OJ: https://oj.leetcode.com/problems/convert-sorted-list-t ...
- LeetCode:Convert Sorted Array to Binary Search Tree,Convert Sorted List to Binary Search Tree
LeetCode:Convert Sorted Array to Binary Search Tree Given an array where elements are sorted in asce ...
- Convert Sorted List to Binary Search Tree&&Convert Sorted Array to Binary Search Tree——暴力解法
Convert Sorted List to Binary Search Tree Given a singly linked list where elements are sorted in as ...
- Leetcode: Convert sorted list to binary search tree (No. 109)
Sept. 22, 2015 学一道算法题, 经常回顾一下. 第二次重温, 决定增加一些图片, 帮助自己记忆. 在网上找他人的资料, 不如自己动手. 把从底向上树的算法搞通俗一些. 先做一个例子: 9 ...
- 【LeetCode】109. Convert Sorted List to Binary Search Tree 解题报告(Python)
[LeetCode]109. Convert Sorted List to Binary Search Tree 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id ...
- 【leetcode】Convert Sorted List to Binary Search Tree
Convert Sorted List to Binary Search Tree Given a singly linked list where elements are sorted in as ...
- Convert Sorted List to Binary Search Tree——将链表转换为平衡二叉搜索树 &&convert-sorted-array-to-binary-search-tree——将数列转换为bst
Convert Sorted List to Binary Search Tree Given a singly linked list where elements are sorted in as ...
随机推荐
- cacti监控linux主机时iptables阻碍了udp161端口造成无法监控解
由于在添加linux主机时,有防火墙启用,造成无法监控linux主机,现有两种方法解决无法监控linux主机问题:可以通过在监控主机执行该命令: snmpwalk -c public -v 2c 19 ...
- QT creator 调试问题
问题:debug出现“ptrace:不允许的操作.” 解决办法: # may not be appropriate for developers or servers with only admin ...
- Qt学习之秒表的实现(StopWatch) (转)
秒表对于我来说并不陌生,在之前自己学习单片机时,实现过秒表和数字钟:基本思路:开启单片机带的定时器,并设置它没10ms溢出一次,分别用三个变量hour,minute,secong记录秒表的时分秒,然后 ...
- Centos用yum升级mysql到(5.5.37) (转)
http://www.cnblogs.com/ikodota/p/use_yum_update_mysql.html 1. Change root user su - ## OR ## sudo -i ...
- 函数参数个数不确定时使用va_start
今天在网上看程序时忽然发现别人的函数参数中有省略号,甚是吃惊,发现其函数中使用了va_start,经过查资料大概明白其用法,个人觉得很好用! #include <stdio.h> #inc ...
- rails里面添加妹子ui
妹子ui看起来很不错,以为在rails里面添加自定义的css和js和平时一样,结果可想而知,不过弄完以后发现还是比较简单的,这里记录一下 妹子ui需要加载的css和js如下 http://cdn.am ...
- STL 算法罗列 (转)
非修改性序列操作(12个) 循环 for_each() 对序列中的每个元素执行某操作 查找 find() 在序列中找出某个值的第一次出现的位置 find_if() 在序列中找出符合某谓词的第一个元素 ...
- 部署docker
部署和开发环境不一样,我们不需要频繁地进入到容器内部,所以一般我们会将代码和环境打包到一块,部署到服务器上 Clone 代码 将项目代码克隆到本地 git clone git@git.coding.n ...
- dubbo相关的知识点总结
dubbo最近提交到了apache,成为了apache的孵化项目,又开始活跃起来了.就官方在git上面的说明文档和其他资料,学习总结以下dubbo的一些知识点. .The dubbo protocol ...
- POJ1745动态规划
Divisibility Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 11622 Accepted: 4178 Des ...