区间树查找

#include<iostream>
#include<queue>
using namespace std;

struct rbnode{
int key;//key值即为low点值
int color;//1=black,0=red;
int max,high;//在每次旋转后更新max
struct rbnode *p,*left,*right;
rbnode(){}
rbnode(int k,int hi){key=k;high=hi;max=hi;
}
};
rbnode *nil;
int max(int a,int b)
{return a>b?a:b;}

int mmax(rbnode * a){
	int xx=-1,yy=-1,zz=-1;
	if(a!=nil)xx=a->high;else return -1;
	if(a->left!=nil)yy=a->left->max;
	if(a->right!=nil)zz=a->right->max;
	return max(max(xx,yy),zz);}

rbnode * Minintervalsearch(rbnode **root,rbnode *x,int i1,int i2);
bool RBinsert(rbnode **root,int k,int high);
void Fixmax(rbnode **root,int num,int high);
void LevelOrder(rbnode *t);
void RBinserFix(rbnode **root,rbnode *z);
void Left(rbnode **root, rbnode *x);
void Right(rbnode **root, rbnode *x);
void Left(rbnode **root, rbnode *x){
	if(x->right!=nil){
		rbnode * y=nil;
	y=x->right;
	x->right=y->left;
	if(y->left!=nil)y->left->p=x;
	y->p=x->p;
	if(x->p==nil) (*root)=y;
	else if(x==x->p->left) x->p->left=y;
	else x->p->right=y;
	y->left=x;
	x->p=y;}
}
void Right(rbnode **root, rbnode *x){
	if(x->left!=nil){
	rbnode * y=nil;
	y=x->left;
	x->left=y->right;
	if(y->right!=nil)y->right->p=x;
	y->p=x->p;
	if(x->p==nil) (*root)=y;
	else if(x==x->p->right) x->p->right=y;
	else x->p->left=y;
	y->right=x;
	x->p=y;
	}
}

void RBinserFix(rbnode **root,rbnode *z){
rbnode* y=nil;

	while(z!=*root&&z->p->color==0){
	if(z->p==z->p->p->left){
		y=z->p->p->right;
		if(y->color==0){
		z->p->color=1;
		y->color=1;
		z->p->p->color=0;
		z=z->p->p;
		}else 
		{		if(z==z->p->right){z=z->p;//LEFT
			Left(root,z);
		//////////////////////////////////////////////
z->max=mmax(z);
z->p->p->max=mmax(z->p->p);
		}
	z->p->color=1;
	z->p->p->color=0;
	//RightRotate();
	Right((root),z->p->p);
///////////////////////////////////////////////////////
	if(z->p!=nil){//z->p不能为nil,否则z->p->left为空
	z->p->max=mmax(z->p);
z->p->right->max=mmax(z->p->right);
	}
		}
		
	
	}else {
		y=z->p->p->left;
		if(y->color==0){
		z->p->color=1;
		y->color=1;
		z->p->p->color=0;
		z=z->p->p;
		}else 
		{		if(z==z->p->left){z=z->p;//LEFT
			Right(root,z);

			z->max=mmax(z);
z->p->p->max=mmax(z->p->p);
			}
	z->p->color=1;
	z->p->p->color=0;
	//RightRotate();
	Left((root),z->p->p);}
if(z->p!=nil)
{	z->p->max=mmax(z->p);
z->p->left->max=mmax(z->p->left);
}
	}
	

	}
	(*root)->color=1;

}
//调节max方法
void Fixmax(rbnode **root,int k,int high){
rbnode* x=*root;
while(x!=nil){

	if(x->max<high)x->max=high;

	if(k==x->key)break;
	if(k<x->key)x=x->left;
	else x=x->right;

}

}

rbnode* Minintervalsearch(rbnode **root,rbnode *x,int i1,int i2){
	rbnode* y=nil;
	if(x==nil)return nil;
if(x->left!=nil&&x->left->max>=i1)
{y=Minintervalsearch(root,x->left,i1,i2);
 if(y!=nil)return y;
	else if((x->key<=i1&&x->high>=i1)||(x->key<=i2&&x->high>=i2)||(x->key>=i1&&x->key<=i2))return x;
	else return nil;
}
else if((x->key<=i1&&x->high>=i1)||(x->key<=i2&&x->high>=i2)||(x->key>=i1&&x->key<=i2))return x;
else return Minintervalsearch(root,x->right,i1,i2);
}



bool RBinsert(rbnode **root,int k,int high){
	rbnode* z=new rbnode(k,high);
	
	//cout<<root->color;
	rbnode* y=nil;

	rbnode* x=*root;
while(x!=nil){
	y=x;
	if(k==x->key)return 0;
	if(k<x->key)x=x->left;
	else x=x->right;
}
	z->p=y;

	if(y==nil) {(*root)=z;(*root)->p=nil;}
else if(k<y->key) y->left=z;
		else y->right=z;
z->left=nil;z->right=nil;
z->color=0;
//LevelOrder(*root);
RBinserFix(root,z);
return 1;
}

void Visit(rbnode *t) {
	if (t) {
		cout << t->key<<'.'<<t->high<<'.'<<t->max;
		if(t->color)cout<<"黑 ";
		else cout<<"红 ";
	}
}

void LevelOrder(rbnode *t) {// 对* t逐层遍历
	queue<rbnode*> Q;
	while (t!=nil) {
		Visit(t); 
		if (t->left!=nil)
			Q.push(t->left);
		if (t->right!=nil)
			Q.push(t->right);
		if (Q.empty())
			break;
		t=Q.front();
		Q.pop();
	}
}


void main(){

//rbnode* root=
//root->color=1;//1=black
//root->p=nil;
//root->left=nil;root->right=nil;
rbnode** root=(rbnode**)malloc(sizeof(rbnode*));;
nil=new rbnode();
nil->color=1;
*root =nil;
	rbnode* y=nil;
//rbnode 
cout<<"输入操作类型：1插入元素 2输出结构 3区间树查找 4退出"<<endl;
int sinin,num,high;
cin>>sinin;
while(sinin!=4)
{switch(sinin){
case 1:
	cout<<"插入： ";
	cin>>num>>high;
	if(num>=high){cout<<"数据范围有问题，重新输入"<<endl;break;}
	if(!RBinsert(root,num,high))cout<<"插入重复值"<<endl;
	else Fixmax(root,num,high);
//	cout<<" root --key:"<<(*root)->p->color<<endl;

	break;
case 2:
	LevelOrder(*root);
	cout<<endl;
	break;
case 3:
	cin>>num>>high;
y=Minintervalsearch(root,*root,num,high);
if(y!=nil)
cout<<y->key<<"    "<<y->high<<endl;
else cout<<"结果为空"<<endl;
	break;
}cout<<"输入操作类型：1插入元素 2输出结构 3区间树查找 4退出"<<endl;
cin>>sinin;
}

}

插入算法基本思想：

区间树，在红黑树的基础上对其进行拓展，增加max域，上限high域，下限key值。利用原key值表示区间的下限，并将key值作为插入时比较的值。通过max来对左子树、右子树及该节点的区间上限做出描述。

查找时，返回与查找区间重叠的最小低端区间，若不存在返回nil，伪代码如下：

MIN-INTERVAL-SEARCH(T,x,i)

{ if left[x]!=nil[T] and max[left[x]]>=low[i]//左子树不为空，且高点大于i低点

{ y=MIN-INTERVAL-SEARCH(T,left[x],i)

if y!=nil return y

else if i overlaps int[x] return x//如果左子树为空则查看节点x，不重叠返回nil

else return nil

}

else if i overlaps int[x]//节点x是否与i重叠

return x