AVL 的基本操作

LL 与 LR

RR 与 RL

插入及建立

#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
struct node{
    
    
	int v, height;
	node *lchild, *rchild;
};

node* newNode(int v)
{
    
    
	node* Node = new node;
	Node->v = v;
	Node->height = 1;
	Node->lchild = NULL;
	Node->rchild = NULL;
	return Node;
}

int getHeight(node* root)
{
    
    
	if(root == NULL) return 0;
	return root->height;
}

int getBalanceFactor(node* root)
{
    
    
	return getHeight(root->lchild) - getHeight(root->rchild);
}

void updateHeight(node* root)
{
    
    
	root->height = max(getHeight(root->lchild), getHeight(root->rchild)) + 1;
}

void L(node* &root)
{
    
    
	node* temp = root->rchild;
	root->rchild = temp->lchild;
	temp->lchild = root;
	updateHeight(root);
	updateHeight(temp);
	root = temp;
}

void R(node* &root)
{
    
    
	node* temp = root->lchild;
	root->lchild = temp->rchild;
	temp->rchild = root;
	updateHeight(root);
	updateHeight(temp);
	root = temp;
}

void insert(node* &root, int v)
{
    
    
	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
				R(root);
			}
			else if(getBalanceFactor(root->lchild) == -1)
			{
    
       // LR
				L(root->lchild);
				R(root);
			}
		}	
	}
	else{
    
    
		 insert(root->rchild, v);
		 updateHeight(root);
		 if(getBalanceFactor(root) == -2)
		 {
    
    
		 	if(getBalanceFactor(root->rchild) == -1)
		 	{
    
      // RR
		 	    L(root);
			}
			else if(getBalanceFactor(root->rchild) == 1)
			{
    
      // RL
				R(root->rchild);
				L(root);
			}
		 }
	}
}

node* Create(int data[], int n)
{
    
    
	node* root = NULL;
	for(int i = 0; i < n; i++)
	{
    
    
		insert(root, data[i]);
	}
	return root;
}

int main()
{
    
    
  
   return 0;
}