Treap树详解-优快云博客

模板：
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;
typedef struct TreapNode* Tree;
typedef int ElementType;
struct TreapNode
{
    ElementType val; //结点值
    int priority;   //优先级
    Tree lchild;
    Tree rchild;
    TreapNode(int val=0,int priority=0) //默认构造函数
    {
        lchild=rchild=NULL;
        this->val=val;
        this->priority=priority;
    }
};
Tree search(Tree &,ElementType);
void right_rotate(Tree &);
void left_rotate(Tree &);
bool insert_val(Tree &,Tree &);
bool insert(Tree &,ElementType,int);
bool remove(Tree &,ElementType);
 
 
//查找函数
Tree search(Tree &root,ElementType val)
{
    if (!root)
        return NULL;
    else if (root->val>val)
       return search(root->lchild,val);
    else if(root->val<val)
      return  search(root->rchild,val);
    return root;
}
//插入函数
bool insert(Tree &root,ElementType val=0,int priority=0)
{
    Tree node=new TreapNode(val,priority);
    return insert_val(root, node);
}
//内部插入函数
//参数:根结点，需插入的结点
bool insert_val(Tree &root,Tree &node)
{
    if (!root)
    {
        root=node; //插入
        return true;
    }
    else if(root->val>node->val)
    {
       bool flag=insert_val(root->lchild, node);
        if (root->priority>node->priority) //检查是否需要调整
            right_rotate(root);
        return flag;
    }
    else if(root->val<node->val)
    {
        bool flag=insert_val(root->rchild, node);
        if (root->priority>node->priority) //检查是否需要调整
            left_rotate(root);
        return flag;
    }
    //已经含有该元素，释放结点
    delete node;
    return false;
 
}
//右旋转
void right_rotate(Tree &node)
{
    Tree temp=node->lchild;
    node->lchild=temp->rchild;
    temp->rchild=node;
    node=temp;
}
//左旋转
void left_rotate(Tree &node)
{
    Tree temp=node->rchild;
    node->rchild=temp->lchild;
    temp->lchild=node;
    node=temp;
}
 
//删除函数
bool remove(Tree &root,ElementType val)
{
    if (root==NULL)
        return false;
    else if (root->val>val)
        return remove(root->lchild,val);
    else if(root->val<val)
        return remove(root->rchild,val);
    else //找到执行删除处理
    {
 
        Tree *node=&root;
        while ((*node)->lchild && (*node)->rchild)  //从该结点开始往下调整
        {
            if ((*node)->lchild->priority<(*node)->rchild->priority) //比较其左右孩子优先级
            {
                right_rotate(*node); //右旋转
                node=&((*node)->rchild); //更新传入参数，进入下一层
            }
            else
            {
                left_rotate(*node); //左旋转
                node=&((*node)->lchild); //更新传入参数，进入下一层
            }
        }
        
        //最后调整到（或者本来是）叶子结点，或者只有一个孩子的情况，可以直接删除了
        if ((*node)->lchild==NULL)
            (*node)=(*node)->rchild;
        else if((*node)->rchild==NULL)
            (*node)=(*node)->lchild;
        return true;
    }
}
 
 
//前序
void PreOrder(Tree root)
{
    if (root==NULL)
        return;
    printf("%d ",root->val);
    PreOrder(root->lchild);
    PreOrder(root->rchild);
}
//中序
void InOrder(Tree root)
{
    if (root==NULL)
        return;
    InOrder(root->lchild);
    printf("%d ",root->val);
    InOrder(root->rchild);
}
int main()
{
    Tree root=NULL;
 
    insert(root,11,6);
    insert(root,7,13);
    insert(root,14,14);
    insert(root,3,18);
    insert(root,9,22);
    insert(root,18,20);
    insert(root,16,26);
    insert(root,15,30);
    insert(root,17,12);
    printf("插入:\n");
    printf("前序:");
    PreOrder(root);
    printf("\n");
    printf("中序:");
    InOrder(root);
    printf("\n");
    printf("删除:\n");
    remove(root,11);
    printf("前序:");
    PreOrder(root);
    printf("\n");
    printf("中序:");
    InOrder(root);
    printf("\n");
    return 0;
}
treap
