转自晴神宝典

struct node{
    int v,height;
    node *lchild,*rchild;
};
node* newNode(int v){//新建节点
    node* Node = new node;
    Node->v = v;
    Node->height = 1;
    Node->lchild = Node->rchild = NULL;
    return Node;
}
int getHeight(node* root){//获取节点高度
    if(root == NULL) return 0;
    return root->height;
}
int getBalanceFactor(node* root){//获取节点平衡因子
    return getHeight(root->lchild)-getHeight(root->rchild);
}
void updateHeight(node* root){//更新节点高度
    root->height=max(getHeight(root->lchild),getHeight(root->rchild))+1;
}
void L(node* &root){//左旋
    node* temp = root->rchild;
    root->rchild = temp->lchild;
    temp->lchild = root;
    updateHeight(root);
    updateHeight(temp);
    root = temp;
}
void R(node* &root){//右旋
    node* temp = root->lchild;
    root->lchild = temp->rchild;
    temp->rchild = root;
    updateHeight(root);
    updateHeight(temp);
    root = temp;
}
void insert(node* &root,int v){//逐步插入节点，边插入，边调节
    if(root == NULL){
        root = newNode(v);
        return;
    }
    if(v < root->v){
        insert(root->lchild,v);
        updateHeight(root);
        if(getBalanceFactor(root) == 2){
            if(getBalanceFactor(root->lchild) == 1){//LL型，直接右旋
                R(root);
            }
            else if(getBalanceFactor(root->lchild) == -1){//LR型，先左子树左旋，然后右旋
                L(root->lchild);
                R(root);
            }
        }
    }
    else{
        insert(root->rchild,v);
        updateHeight(root);
        if(getBalanceFactor(root) == -2){
            if(getBalanceFactor(root->rchild) == -1){//RR型直接左旋
                L(root);
            }
            else if(getBalanceFactor(root->rchild) == 1){//RL型先右子树右旋，然后左旋
                R(root->rchild);
                L(root);
            }
        }    	
    }
}
node* Creat(int data[],int n){
    node* root = NULL;
    for(int i=0;i<n;i++){
        insert(root,data[i]);
    }
    return root;
}