https://leetcode.com/problems/complete-binary-tree-inserter/

给出树节点的定义和完全二叉树插入器类的定义,为这个类补全功能。完全二叉树的定义为:这颗二叉树除最后一层外左右层的节点都是满的(对于第i层有2^(i-1)个节点),最后一层节点都出现在尽量靠左的位置。

/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class CBTInserter {
public:
CBTInserter(TreeNode* root) {}
int insert(int v) {}
TreeNode* get_root() {}
};
/**
* Your CBTInserter object will be instantiated and called as such:
* CBTInserter* obj = new CBTInserter(root);
* int param_1 = obj->insert(v);
* TreeNode* param_2 = obj->get_root();

解法一:

我的思路是,先遍历给定二叉树,得到树的深度maxlayer和最后一层的节点数numoflastlayer。若numoflastlayer<2^(maxlayer-1),则新节点插入在第layer=maxlayer层;若numoflastlayer=2^(maxlayer-1),说明最后一层满了,需要插入到第layer=maxlayer+1层。再先序遍历这棵树,遍历到第layer-1层的节点时,判断:若节点只有左节点,则将新节点作为其右孩子;若节点无子节点,则将新节点作为其左孩子。

class CBTInserter
{
public:
void preorder(TreeNode* root,int layer)
{
if(layer>maxlayer)
{
maxlayer = layer;
numoflastlayer = ;
}
else if(layer == maxlayer)
numoflastlayer++;
if(root->left!=NULL)
preorder(root->left, layer+);
if(root->right!=NULL)
preorder(root->right, layer+);
}
CBTInserter(TreeNode* root)
{
root_ =root;
maxlayer=-;
numoflastlayer=;
preorder(root,);
} TreeNode* Insert(TreeNode* root, int v, int layer, int insertlayer)
{
if(layer == insertlayer-)
{
if(root->left == NULL)
{
root->left = new TreeNode(v);
return root;
}
else if(root->right == NULL)
{
root->right = new TreeNode(v);
return root;
}
}
else
{
TreeNode* res = Insert(root->left, v, layer+, insertlayer);
if(res == NULL)
res = Insert(root->right, v, layer+, insertlayer);
return res;
}
return NULL;
} int insert(int v)
{
cout<<v<<endl;
int maxnumoflastlayer = pow(, maxlayer);
TreeNode* res = NULL;
if(numoflastlayer<maxnumoflastlayer)
{
res = Insert(root_,v,, maxlayer);
numoflastlayer++;
}
else
{
res = Insert(root_,v,,maxlayer+);
maxlayer++;
numoflastlayer=;
}
return res->val;
} TreeNode* get_root()
{
return root_;
}
private:
TreeNode* root_;
int maxlayer;
int numoflastlayer;
};

解法二:新节点插入的位置的父节点的子节点数要么为1,要么为0。根据层次遍历,把节点子节点数为0或1的节点存入队列。插入时,取队头节点,若该节点有左孩子,则将新节点作为其右孩子,并将该左右孩子压入队尾,将该队头节点出队;若该节点无孩子,则将新节点作为其左孩子,该节点仍然作为队头节点。

class CBTInserter
{
public:
TreeNode* root_;
queue<TreeNode*> nodes_0_1;
CBTInserter(TreeNode* root)
{
root_ = root;
queue<TreeNode*> que;
que.push(root);
while(!que.empty())
{
TreeNode* now = que.front();
que.pop();
if(now->left == NULL)
nodes_0_1.push(now);
else if(now->right == NULL)
nodes_0_1.push(now);
else
{
que.push(now->left);
que.push(now->right);
}
}
} int insert(int v)
{
TreeNode* root = nodes_0_1.front();
if(root->left!=NULL)
{
root->right = new TreeNode(v);
nodes_0_1.pop();
nodes_0_1.push(root->left);
nodes_0_1.push(root->right);
}
else
root->left = new TreeNode(v);
return root->val;
} TreeNode* get_root()
{
return root_;
}
};

leetcode_919. Complete Binary Tree Inserter_完全二叉树插入的更多相关文章

  1. [LeetCode] 919. Complete Binary Tree Inserter 完全二叉树插入器

    A complete binary tree is a binary tree in which every level, except possibly the last, is completel ...

  2. PAT 1110 Complete Binary Tree[判断完全二叉树]

    1110 Complete Binary Tree(25 分) Given a tree, you are supposed to tell if it is a complete binary tr ...

  3. leetcode_919. Complete Binary Tree Inserter

    https://leetcode.com/problems/complete-binary-tree-inserter/ 设计一个CBTInserter,使用给定完全二叉树初始化.三个功能; CBTI ...

  4. [Swift]LeetCode919. 完全二叉树插入器 | Complete Binary Tree Inserter

    A complete binary tree is a binary tree in which every level, except possibly the last, is completel ...

  5. PAT A1110 Complete Binary Tree (25 分)——完全二叉树,字符串转数字

    Given a tree, you are supposed to tell if it is a complete binary tree. Input Specification: Each in ...

  6. [二叉树建树&完全二叉树判断] 1110. Complete Binary Tree (25)

    1110. Complete Binary Tree (25) Given a tree, you are supposed to tell if it is a complete binary tr ...

  7. PAT甲级——1110 Complete Binary Tree (完全二叉树)

    此文章同步发布在CSDN上:https://blog.csdn.net/weixin_44385565/article/details/90317830   1110 Complete Binary ...

  8. 【LeetCode】919. Complete Binary Tree Inserter 解题报告(Python & C++)

    作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址: https://leetcode. ...

  9. PAT1110:Complete Binary Tree

    1110. Complete Binary Tree (25) 时间限制 400 ms 内存限制 65536 kB 代码长度限制 16000 B 判题程序 Standard 作者 CHEN, Yue ...

随机推荐

  1. SPOJ:Easy Factorials(占位)

    Finding factorials are easy but they become large quickly that is why Lucky hate factorials. Today h ...

  2. 线段树之成段更新( 需要用到延迟标记,简单来说就是每次更新的时候不要更新到底,用延迟标记使得更新延迟到下次需要更新or询问到的时候)

    HDU  1698 链接:  http://acm.hdu.edu.cn/showproblem.php?pid=1698 线段树功能:update:成段替换 (由于只query一次总区间,所以可以直 ...

  3. Collection View Programming Guide for iOS---(五)---Incorporating Gesture Support

      Incorporating Gesture Support 结合手势支持 You can add greater interactivity to your collection views th ...

  4. MySQL的分支

    1.MariaDB MariaDB数据库管理系统是 MySQL 的一个分支,主要由开源社区在维护,采用GPL授权许可 MariaDB的目的是完全兼容MySQL,包括API和命令行,使之能轻松成为MyS ...

  5. Tasks 多核查找最大最小值问题

    先贴下代码 _Datas.ParallelForEach(arg_nDataStartIndex, arg_nDataCount, (data) => { dMax = dMax.Max(dat ...

  6. DataGridTemplateColumn 如何获取内部控件

    WPF中有时候我们不使用DataGridTextColumn 而使用用途更加宽广的DataGridTemplateColumn 但是用途多的东西当然也更复杂. 这里说下如何取DataGridTempa ...

  7. Log2Net组件代码详解(附开源代码)

    上一篇,我们介绍了Log2Net的需求和整体框架,我们接下来介绍我们是如何用代码实现Log2Net组件的功能的. 一.整体介绍 Log2Net组件本身是一个Dll,供其他系统调用. 本部分由以下几部分 ...

  8. (十)SpringBoot的文件上传

    一:添加commons-fileupload依赖 打开pom文件添加 <dependency> <groupId>commons-fileupload</groupId& ...

  9. mybaits 连接数据库汉字保存乱码??

    查看数据库连接地址: jdbc.url=jdbc:mysql://localhost:3306/az?useUnicode=true&characterEncoding=utf-8 多了一个a ...

  10. AtCoder Grand Contest 016 E - Poor Turkeys

    题目传送门:https://agc016.contest.atcoder.jp/tasks/agc016_e 题目大意: 有\(N\)只火鸡,现有\(M\)个人,每个人指定了两只火鸡\(x,y\),每 ...