AVL树模版

最新推荐文章于 2025-08-23 16:06:02 发布

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最新推荐文章于 2025-08-23 16:06:02 发布

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本文链接：https://blog.youkuaiyun.com/sinat_33397705/article/details/52445290

本文详细介绍了AVL树的插入操作及四种旋转调整方法：左旋(LL)、右旋(RR)、左右旋(LR)和右左旋(RL)。通过具体的C++实现代码，展示了如何保持AVL树的平衡特性。

#include<stdio.h>
#include<string.h>
#include<iostream>
using namespace std;
struct AVL_tree_node
{
    char name[31];
    int cnt,height;
    AVL_tree_node *pleft;
    AVL_tree_node *pright;
};
int n=0;
int Height(AVL_tree_node *p)
{
    if(p==NULL) return -1;
    return p->height;
}
AVL_tree_node* LLRotate(AVL_tree_node *Root)
{
    AVL_tree_node *p=Root->pleft;
    Root->pleft=p->pright;
    p->pright=Root;

    Root->height=max(Height(Root->pleft),Height(Root->pright))+1;
    p->height=max(Height(p->pleft),Root->height)+1;
    return p;
}
AVL_tree_node* RRRotate(AVL_tree_node *Root)
{
    AVL_tree_node *p=Root->pright;
    Root->pright=p->pleft;
    p->pleft=Root;

    Root->height=max(Height(Root->pleft),Height(Root->pright))+1;
    p->height=max(Height(p->pright),Root->height)+1;
    return p;
}
AVL_tree_node* LRRotate(AVL_tree_node *Root)
{
    Root->pleft=RRRotate(Root->pleft);
    return LLRotate(Root);
}
AVL_tree_node* RLRotate(AVL_tree_node *Root)
{
    Root->pright=LLRotate(Root->pright);
    return RRRotate(Root);
}
AVL_tree_node* Insert(char s[],AVL_tree_node *Root)
{
    if(Root==NULL)
    {
        Root=new AVL_tree_node;
        strcpy(Root->name,s);
        Root->cnt=1;
        Root->height=0;
        Root->pleft=Root->pright=NULL;
        return Root;
    }
    int t=strcmp(s,Root->name);
    if(t==0)
    {
        Root->cnt++;
    }
    else if(t<0)
    {
        Root->pleft=Insert(s,Root->pleft);
        if(Height(Root->pleft)-Height(Root->pright)==2)
        {
            if(strcmp(s,Root->pleft->name)<0) Root=LLRotate(Root);
            else Root=LRRotate(Root);
        }
    }
    else
    {
        Root->pright=Insert(s,Root->pright);
        if(Height(Root->pright)-Height(Root->pleft)==2)
        {
            if(strcmp(s,Root->pright->name)>0) Root=RRRotate(Root);
            else Root=RLRotate(Root);
        }
    }
    Root->height=max(Height(Root->pleft),Height(Root->pright))+1;
    return Root;
}
void mid_cal(AVL_tree_node *Root)
{
    if(Root!=NULL)
    {
        mid_cal(Root->pleft);
        printf("%s %.4lf\n",Root->name,Root->cnt*100.0/n);
        mid_cal(Root->pright);
    }
}
int main()
{
    AVL_tree_node *Root=NULL;
    char s[31];
    while(gets(s)!=NULL)
    {
        Root=Insert(s,Root);
        n++;
    }
    mid_cal(Root);
}