数据结构实验之查找二：平衡二叉树oj

最新推荐文章于 2022-03-09 16:12:36 发布

原创最新推荐文章于 2022-03-09 16:12:36 发布 · 307 阅读

1 ·

CC 4.0 BY-SA版权

二叉树专栏收录该内容

20 篇文章

订阅专栏

本文介绍如何根据给定的整数序列构建平衡二叉树，并通过一系列旋转操作确保树的平衡性，最终输出树的根节点值。

数据结构实验之查找二：平衡二叉树

Time Limit: 400MS Memory Limit: 65536KB

Problem Description

根据给定的输入序列建立一棵平衡二叉树，求出建立的平衡二叉树的树根。

Input

输入一组测试数据。数据的第1行给出一个正整数N(n <= 20)，N表示输入序列的元素个数；第2行给出N个正整数，按数据给定顺序建立平衡二叉树。

Output

输出平衡二叉树的树根。

Example Input

5
88 70 61 96 120

Example Output

Hint

Author

xam

#include <stdio.h>
#include <stdlib.h>
struct node
{
    int data;
    int d;
    struct node *lchild,*rchild;
};

int max(int x,int y)
{
    return x>y ? x:y;
}

int Deep(struct node *head)
{
    if (!head)
        return -1;
    else return head->d;
}

struct node *LL(struct node *head)//右旋
{
    struct node *p = head->lchild;
    head->lchild = p->rchild;
    p->rchild = head;
    p->d = max(Deep(p->lchild),Deep(p->rchild))+1;
    head->d = max(Deep(head->lchild),Deep(head->rchild))+1;
    return p;
}


struct node *RR(struct node *head)//左旋
{
    struct node *p = head->rchild;
    head->rchild = p->lchild;
    p->lchild = head;
    p->d = max(Deep(p->lchild),Deep(p->rchild))+1;
    head->d = max(Deep(head->lchild),Deep(head->rchild))+1;
    return p;
}

struct node *LR(struct node *head)
{
    head->lchild = RR(head->lchild);//先做左旋
    return LL(head);//在做右旋
}
struct node *RL(struct node *head)
{
    head->rchild = LL(head->rchild);//先做右旋
    return RR(head);//在做左旋
}

struct node *Creat(struct node *head,int x)
{
    if (head == NULL)
    {
        head = (struct node *)malloc (sizeof (struct node));
        head->data = x;
        head->d = 0;
        head->rchild = head->lchild = NULL;
    }
    else if (head->data > x)
    {
        head->lchild = Creat(head->lchild,x);
        if (Deep(head->lchild)-Deep(head->rchild)>1)
        {
            if (head->lchild->data > x)
                head = LL(head);
            else
                head = LR(head);
        }
    }
    else if (head->data < x)
    {
        head->rchild  = Creat(head->rchild,x);
        if (Deep(head->rchild)-Deep(head->lchild)>1)
        {
            if (head->rchild->data > x)
                head = RL(head);
            else
                head = RR(head);
        }
    }
    head->d = max(Deep(head->lchild),Deep(head->rchild))+1;
    return head;
}

int main()
{
    int n,m;
    scanf ("%d",&n);
    struct node *head = NULL;
    for (int i=0; i<n; i++)
    {
        scanf ("%d",&m);
        head = Creat(head,m);
    }
    printf ("%d\n",head->data);
    return 0;
}