标签:node lchild int root getbalance Tree AVL rchild Root
An AVL tree is a self-balancing binary search tree. In an AVL tree, the heights of the two child subtrees of any node differ by at most one; if at any time they differ by more than one, rebalancing is done to restore this property. Figures 1-4 illustrate the rotation rules.
Now given a sequence of insertions, you are supposed to tell the root of the resulting AVL tree.
Input Specification:
Each input file contains one test case. For each case, the first line contains a positive integer N (≤20) which is the total number of keys to be inserted. Then N distinct integer keys are given in the next line. All the numbers in a line are separated by a space.
Output Specification:
For each test case, print the root of the resulting AVL tree in one line.
Sample Input 1:
5
88 70 61 96 120
Sample Output 1:
70
Sample Input 2:
7
88 70 61 96 120 90 65
Sample Output 2:
88
代码:
#include<iostream>
#include<algorithm>
using namespace std;
int N;
int num[25];
struct node//定义树的结点
{
int height;//存放树的高度,用以间接获得结点的平衡因子
int data;
node* lchild;
node* rchild;
};
int getheight(node *root)//获得结点的高度
{
if(root==NULL)
return 0;
else
return root->height;
}
void updataheight(node *root)//更新结点root的高度,为左右子树中高度高的一个+1
{
root->height=max(getheight(root->lchild),getheight(root->rchild))+1;
}
int getbalance(node *root)//获得结点的平衡因子(=左子树高度-右子树高度)
{
return getheight(root->lchild)-getheight(root->rchild);
}
void L(node * &root)//左旋
{
node *p=root->rchild;
root->rchild=p->lchild;
p->lchild=root;
updataheight(root);
updataheight(p);
root=p;
}
void R(node * &root)//右旋
{
node *p=root->lchild;
root->lchild=p->rchild;
p->rchild=root;
updataheight(root);
updataheight(p);
root=p;
}
void insert(node *&root,int x)//插入x,注意root要用引用
{
if(root==NULL)
{
root=new node;
root->data=x;
root->lchild=NULL;
root->rchild=NULL;
root->height=1;
return;
}
if(root->data>x)
{
insert(root->lchild,x);
updataheight(root);
if(getbalance(root)==2)//调整树为平衡二叉树
{
if(getbalance(root->lchild)==1)//为LL型,进行右旋
R(root);
else if(getbalance(root->lchild)==-1)//为LR型,先左旋,在右旋
{
L(root->lchild);
R(root);
}
}
}
else
{
insert(root->rchild,x);
updataheight(root);
if(getbalance(root)==-2)
{
if(getbalance(root->rchild)==-1)//为RR型,进行左旋
L(root);
else if(getbalance(root->rchild)==1)//为RL型,先右旋,在左旋
{
R(root->rchild);
L(root);
}
}
}
}
node* creat()
{
node *root=NULL;
for(int i=0;i<N;i++)
insert(root,num[i]);
return root;
}
int main()
{
scanf("%d",&N);
for(int i=0;i<N;i++)
scanf("%d",num+i);
node *root=creat();
printf("%d",root->data);
return 0;
}
标签:node,lchild,int,root,getbalance,Tree,AVL,rchild,Root 来源: https://blog.csdn.net/fairylyt/article/details/123169499
本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享; 2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关; 3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关; 4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除; 5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。