平衡二叉树

#include<bits/stdc++.h>
#define MaxSize 100
using namespace std;

typedef struct AVLNode *Position;
typedef Position AVLTree;
struct AVLNode{
    int data;
    AVLTree Left;
    AVLTree Right;
    int Height;
};
int Max(int a,int b){
    return a>b?a:b;
}
AVLTree SingleLeftRotation(AVLTree A){
    //A必须有一个左子结点B
    //将A与B做左单旋（LL），更新A与B的高度，返回新的根结点B
    AVLTree B = A->Left;
    A->Left = B->Right;
    B->Right = A;
    A->Height = Max(getheight(A->Left),getheight(A->Right))+1;
    B->Height = Max(getheight(B->Left),A->Height)+1;
    return B;
}
AVLTree SingleRightRotation(AVLTree A){
    //A有右子结点B，RR
    AVLTree B = A->Right;
    A->Right = B->Left;
    B->Left = A;
    A->Height = Max(getheight(A->Left),getheight(A->Right))+1;
    B->Height = Max(getheight(B->Right),A->Height)+1;
    return B;
}

AVLTree DoubleLeftRightPotation(AVLTree A){
    //A有左子结点B，B有右结点C，LR旋转
    A->Left = SingleRightRotation(A->Left);//BandC
    return SingleLeftRotation(A);//AandC LL
}

AVLTree DoubleRightLeftPotation(AVLTree A){
    //RL
    A->Right = SingleLeftRotation(A->Right);
    return SingleRightRotation(A);
}

//插入
AVLTree Insert(AVLTree T,int X){
    if(!T){
        T = (AVLTree)malloc(sizeof(struct AVLNode));
        T->data = X;
        T->Height = 0;
        T->Right = T->Left = NULL;
    }
    else if(X < T->data){
        T->Left = Insert(T->Left,X);
        if(getheight(T->Left)-getheight(T->Right) == 2)
            if(X<T->Left->data)
                T = SingleLeftRotation(T);
            else
                T = DoubleLeftRightPotation(T);
    }
    else if(X > T->data){
        T->Right = Insert(T->Right,X);
        if(getheight(T->Left)-getheight(T->Right) == -2)
            if(X > T->Right->data)
                T = SingleRightRotation(T);
            else
                T = DoubleRightLeftPotation(T);
    }
    T->Height = Max(getheight(T->Left),getheight(T->Right))+1;
    return T;
}

标签：Right,int,AVLTree,getheight,Height,二叉树,平衡,Left
来源： https://www.cnblogs.com/warmingtxdy/p/12098836.html