二叉平衡树

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;

struct TreeNode{
    int data;
    TreeNode* lchild, *rchild;
    int freq, height;
};

class AVLTree{
public:
    TreeNode *head;
    AVLTree(){
        head = NULL;
    }
    void Insert(int x, TreeNode* &cur){
        if(cur == NULL){
            cur = new TreeNode;
            cur->data = x;
            cur->lchild = cur->rchild = NULL;
            cur->freq = cur->height = 1;
        }
        else if(x < cur->data){
            Insert(x, cur->lchild);
            if(2 == CampHeight(cur->lchild, cur->rchild)){
                if(x < cur->lchild->data) LL(cur);
                else LR(cur);
            }
        }
        else if(x > cur->data){
            Insert(x, cur->rchild);
            if(2 == CampHeight(cur->rchild, cur->lchild)){
                if(x > cur->rchild->data) RR(cur);
                else RL(cur);
            }
        }
        else
            cur->freq++;
    }
    void InOrder(TreeNode* t){
        if(t == NULL) return;
        InOrder(t->lchild);
        cout << t->data << " ";
        InOrder(t->rchild);
    }
private:
    void LL(TreeNode* t){
        TreeNode* tmp = t->lchild;
        t->lchild = tmp->rchild;
        tmp->rchild = t;
        GainHeight(t);
        GainHeight(tmp);
    }
    void RR(TreeNode* t){
        TreeNode* tmp = t->rchild;
        t->rchild = tmp->lchild;
        tmp->lchild = t;
        GainHeight(t);
        GainHeight(tmp);
    }
    void LR(TreeNode* t){
        RR(t->lchild);
        LL(t);
    }
    void RL(TreeNode* t){
        LL(t->rchild);
        RR(t);
    }
    void GainHeight(TreeNode* t){
        if(t == NULL) return;
        if(t->lchild != NULL && t->rchild != NULL)
            t->height = (t->lchild->height > t->rchild->height ? t->lchild->height : t->rchild->height) + 1;
        else if(t->lchild == NULL && t->rchild == NULL)
            t->height = 1;
        else if(t->lchild != NULL)
            t->height = t->lchild->height + 1;
        else
            t->height = t->rchild->height + 1;
    }
    int CampHeight(TreeNode* p, TreeNode* q){
        if(p != NULL && q != NULL)
            return p->height - q->height;
        else if(p == NULL && q == NULL)
            return 0;
        else if(p != NULL)
            return p->height;
        else
            return -q->height;
    }
};
int main(){
    int arr[] = {6,7,3,5,3,2,1,78,45,65};
    AVLTree tree;
    for(int i = 0; i < sizeof(arr)/sizeof(int); i++){
        tree.Insert(arr[i], tree.head);
    }
    tree.InOrder(tree.head);
    cout << endl;
    return 0;
}