5-31笛卡尔树(25 分)

#include <iostream>
#include "queue"
#include "deque"
#include "algorithm"
#include "string.h"
using namespace std;

#define Max 100
struct Le
{
	int k1,k2;
	int left,right;
};
Le A[Max];
int Examine[Max];
struct Node
{
   int K1;
   int K2;
   Node *Left;
   Node *Right;
};
deque<int>Q1,Q2;
class Tree
{
private:
	Node *root;
public:
	Tree(){root=NULL;}
    Node*& Root(){return root;}
	void Output(Node *p);
	void Output();
	void JudgeK1(Node *p);
    void JudgeK1();
	bool JudgeK2(Node *p);
	bool JudgeK2();
};
bool Tree::JudgeK2()
{
   return JudgeK2(root);
}
bool Tree::JudgeK2(Node *p)
{
   if(p==NULL) return true;
   if(p->Left==NULL && p->Right==NULL) return true;
   if(p->Left!=NULL && p->Right==NULL)
   { 
      if(p->K2<p->Left->K2) return true;
	  return false;
   }
   if(p->Left==NULL && p->Right!=NULL)
   {
	   if(p->K2<p->Right->K2) return true;
	   return false;
   }
   bool T1,T2;
   T1=JudgeK2(p->Left);
   T2=JudgeK2(p->Right);
   
   if(T1 && T2) return true;
    return false;

}
void Tree::JudgeK1()
{ 
   JudgeK1(root);
}
void Tree::JudgeK1(Node *p)
{
	if(p!=NULL)
	{
		JudgeK1(p->Left);
	    Q1.push_back(p->K1);
		Q2.push_back(p->K1);
		JudgeK1(p->Right);
	}
}
void Build(Node *&p,int i)
{ 
	p=new Node;
	p->K1=A[i].k1;
	p->K2=A[i].k2;
	if(A[i].left!=-1)
	{
		Build(p->Left,A[i].left);
	}
    else p->Left=NULL;
    if(A[i].right!=-1)
	{
		Build(p->Right,A[i].right);
	}
	else p->Right=NULL;
}

int main()
{   

   memset(Examine,0,sizeof(Examine));
   int n,i;
   cin>>n;
   for(i=0;i<n;i++)
   {
	 cin>>A[i].k1>>A[i].k2>>A[i].left>>A[i].right;
	 if(A[i].left!=-1) Examine[A[i].left]=1;
	 if(A[i].right!=-1) Examine[A[i].right]=1;
   }
   int root=0;
   while(Examine[root]==1)
   root++;
   Tree tree;    
   Build(tree.Root(),root); 
   bool flag=true;    
   
   tree.JudgeK1();
   
   sort(Q2.begin(),Q2.end());

   for(i=0;i<Q1.size();i++)
   {
	   if(Q1[i]>Q2[i])
	   flag=false;
   }
   if(flag==false)
   {
	   cout<<"NO"<<endl;
   }
   else
   {
	   if(tree.JudgeK2())
		   cout<<"YES"<<endl;
	   else
		   cout<<"NO"<<endl;
   }
   
    
    
   
    return 0;
}