treapツリーおよび関連アルゴリズム

#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct treenode
{
    int key;
    int priority;
    int flag;
    treenode* parent;
    treenode* lchild;
    treenode* rchild;
    
}node,*pnode;
pnode treeroot=NULL;
void adjusttree(pnode p)
{
    
    if(p->parent==NULL)return;
    if(p->priority>=p->parent->priority)return;
    if(p->flag==1)//p lie in the left subtree, rotate right
    {
        pnode prt=p->parent,rchild=p->rchild;
        if(p->parent->flag==0)
        {
            prt->lchild=rchild;
            if(rchild)rchild->parent=prt;
            if(rchild)rchild->flag=1;
            p->rchild=prt;
            prt->parent=p;
            prt->flag=2;
            treeroot=p;
            p->parent=NULL;
            p->flag=0;
            return;
        }
        else if(p->parent->flag==1)
        {
            pnode grdp=prt->parent;
            prt->lchild=rchild;
            if(rchild)rchild->parent=prt;
            if(rchild)rchild->flag=1;
            p->rchild=prt;
            prt->parent=p;
            prt->flag=2;
            grdp->lchild=p;
            p->parent=grdp;
            p->flag=1;
            adjusttree(p);
        }
        else if(p->parent->flag==2)
        {
            pnode grdp=prt->parent;
            prt->lchild=rchild;
            if(rchild)
                rchild->parent=prt;
            if(rchild)
                rchild->flag=1;
            p->rchild=prt;
            prt->parent=p;
            prt->flag=2;
            grdp->rchild=p;
            p->parent=grdp;
            p->flag=2;
            adjusttree(p);
        }
    
    }
    else if(p->flag==2)//p lie in the right tree, rotate left
    {
        pnode prt=p->parent,lchild=p->lchild;
        if(p->parent->flag==0)
        {
            prt->rchild=lchild;
            if(lchild)lchild->parent=prt;
            if(lchild)lchild->flag=2;
            p->lchild=prt;
            prt->parent=p;
            prt->flag=1;
            treeroot=p;
            p->parent=NULL;
            p->flag=0;
            return;

        }
        else if(p->parent->flag==1)
        {
            pnode grdp=prt->parent;
            prt->rchild=lchild;
            if(lchild)lchild->parent=prt;
            if(lchild)lchild->flag=2;
            p->lchild=prt;
            prt->parent=p;
            prt->flag=1;
            grdp->lchild=p;
            p->parent=grdp;
            p->flag=1;
            adjusttree(p);
        }
        else if(p->parent->flag==2)
        {
            pnode grdp=prt->parent;
            prt->rchild=lchild;
            if(lchild)lchild->parent=prt;
            if(lchild)lchild->flag=2;
            p->lchild=prt;
            prt->parent=p;
            prt->flag=1;
            grdp->rchild=p;
            p->parent=grdp;
            p->flag=2;
            adjusttree(p);
        }
        
    }

}
void insert_node(pnode root,pnode p,pnode parent,int flag)
{
    if(root==NULL)
    {
        p->flag=flag;
        p->parent=parent;
        if(flag==1)parent->lchild=p;
        if(flag==2)parent->rchild=p;
        if(p->priority<p->parent->priority)adjusttree(p);
        return;
    }
    if(root->key>=p->key)insert_node(root->lchild,p,root,1);
    else insert_node(root->rchild,p,root,2);
}
pnode createnode(int key,int priority)
{
    pnode tmp;
    tmp=(pnode)malloc(sizeof(node));
    tmp->flag=0;
    tmp->parent=NULL;
    tmp->rchild=NULL;
    tmp->lchild=NULL;
    tmp->key=key;
    tmp->priority=priority;
    return tmp;
}
void dsptree(pnode p)
{
    if(p)dsptree(p->lchild);
    if(p){printf("#%dsubtree key=%d
",p->flag,p->key);}
    if(p)dsptree(p->rchild);
}
int main()
{
    treeroot=createnode(10,8);
    pnode n1=createnode(6,5);
    pnode n2=createnode(2,3);
    pnode n3=createnode(4,3);
    pnode n4=createnode(9,2);
    insert_node(treeroot,n1,0,0);
    insert_node(treeroot,n2,0,0);
    insert_node(treeroot,n3,0,0);
    insert_node(treeroot,n4,0,0);
    dsptree(treeroot);
    system("pause");
    return 0;
}