数据结构实验之查找二：平衡二叉树

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

70

Hint

Author
xam

#include<stdio.h>#include<stdlib.h>struct node{    int data;    int h;    struct node *lchild,*rchild;};int MyMax(int x,int y){    return x>y?x:y;}int deep(struct node *t){    if(t==NULL)return -1;    else return t->h;}struct node *LL(struct node *t){    struct node *q;    q = t -> lchild;    t -> lchild = q -> rchild;    q -> rchild = t;    q -> h = MyMax(deep(q->lchild),deep(q->rchild)) + 1;    t -> h = MyMax(deep(t->lchild),deep(t->rchild)) + 1;    return q;}struct node *RR(struct node *t){    struct node *q;    q = t -> rchild;    t -> rchild = q -> lchild;    q -> lchild = t;    q -> h = MyMax(deep(q->lchild),deep(q->rchild)) + 1;    t -> h = MyMax(deep(t->lchild),deep(t->rchild)) + 1;    return q;}struct node *LR(struct node *t){    struct node *q,*tail;    q = t -> lchild;    tail = q -> rchild;    q -> rchild = tail -> lchild;    tail -> lchild = q;    t->lchild = tail -> rchild;    tail -> rchild = t;    tail -> h = MyMax(deep(tail->lchild),deep(tail->rchild)) + 1;    q -> h = MyMax(deep(q->lchild),deep(q->rchild)) + 1;    t -> h = MyMax(deep(t->lchild),deep(t->rchild)) + 1;    return tail;}//或者用//struct node *LR(struct node *t)//{  //t->lchild = RR(t->lchild);//先做左旋  //return LL(t);//在做右旋//}  struct node *RL(struct node *t){     struct node *q,*tail;     q = t -> rchild;     tail = q -> lchild;     q -> lchild = tail -> rchild;     tail -> rchild = q;     t -> rchild = tail -> lchild;     tail -> lchild = t;    tail -> h = MyMax(deep(tail->lchild),deep(tail->rchild)) + 1;    q -> h = MyMax(deep(q->lchild),deep(q->rchild)) + 1;    t -> h = MyMax(deep(t->lchild),deep(t->rchild)) + 1;    return tail;}//struct node *RL(struct node *t)//{//  t->rchild = LL(t->rchild);//先做右旋//  return RR(t);//在做左旋//}struct node *creat(struct node *root,int x){    if(root==NULL)    {        root = (struct node *)malloc(sizeof(struct node));        root -> data = x;        root -> h = 0;        root -> lchild = root -> rchild = NULL;    }    else if(x < root->data)    {        root -> lchild = creat(root -> lchild,x);        if(deep(root->lchild) - deep(root->rchild) > 1)        {            if(x < root->lchild->data)                root = LL(root);            else root = LR(root);        }    }    else if(x > root->data)    {        root -> rchild = creat(root->rchild,x);        if(deep(root->rchild) - deep(root->lchild) > 1)        {            if(x < root->rchild->data)                root = RL(root);            else root = RR(root);        }    }    root -> h = MyMax(deep(root->lchild),deep(root->rchild)) + 1;    return root;}int main(){    struct node *root;    root = NULL;    int n,i;    scanf("%d",&n);    for(i = 0;i < n;i++)    {        int x;        scanf("%d",&x);        root = creat(root,x);    }    printf("%d\n",root->data);    return 0;}