BZOJ 3196 二x平衡树

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Solution

外层区间线段树，内层平衡树存数值。K值用到二分答案，比较经典。 之前写过，为了试试新的代码写法，写了一遍。结果Treap旋转的时候没有更新信息，WA了一次。

Code

treap在trans的时候没有pushup 

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//Code by Lucida
#include<bits/stdc++.h>
#define get(x) scanf("%d",&x)
#define put(x) printf("%d\n",x)
//#define debug(x) std::cout<<#x<<'='<<x<<std::endl
template <class T> inline bool chkmx(T &a,const T &b){return a<b?a=b,1:0;}
template <class T> inline bool chkmn(T &a,const T &b){return a>b?a=b,1:0;}
const int MAXN=50000+10,INF=0x1f1f1f1f;
using std::max;
using std::min;
namespace IO
{
	#ifndef get
	const int INBUF=1e6;
	char in[INBUF],*iptr=in,*iend=in;
	#define getc() ( (iptr==iend && (iend=(iptr=in)+fread(in,1,INBUF,stdin),iptr==iend))?EOF:*iptr++ )
	inline void get(int &x)
	{
		static int f,ch;
		f=1;
		while(!isdigit(ch=getc())) if(ch=='-') f=-1;
		x=ch-'0';
		while(isdigit(ch=getc())) (x*=10)+=ch-'0';
		x*=f;
	}
	#endif
	#ifndef put
	const int OUTBUF=1e6;
	char out[OUTBUF],*optr=out,*oend=out+OUTBUF-1;
	#define putc(x) (optr==oend?(fwrite(out,1,optr-out,stdout),optr=out,*optr++=(x)):*optr++=(x))
	inline void put(int x)
	{
		if(x==0) putc('0');
		if(x<0) putc('-'),x=-x;
		if(x)
		{
			static int stack[100],*top=stack;
			while(x) *++top=x%10,x/=10;
			while(top!=stack) putc((*top--)+'0');
		}
		putc('\n');
	}
	#endif
	void flush()
	{
		#ifndef put
		fwrite(out,1,optr-out,stdout);
		#endif
	}
}
using namespace IO;

namespace Treap
{
	const int P=1e5+7;
	struct Node
	{
		Node *son[2];
		int v,py,sz,cnt;
		Node(){py=P;sz=0;}
		void up(){sz=cnt+son[0]->sz+son[1]->sz;}
		int LowCount(int);
		int Pred(int);
		int Succ(int);
	}*null=new Node;

	void out(Node *pos)
	{
		if(pos==null) return;
		out(pos->son[0]);printf("%d(%d)  ",pos->v,pos->cnt);out(pos->son[1]);
	}

	Node *newNode(int v)
	{
		static const int SIZE=MAXN*30;
		static Node *ME=(Node*)malloc(SIZE*sizeof(Node)),*cur;
		cur=ME++;cur->v=v;cur->py=rand()%P;cur->cnt=cur->sz=1;
		cur->son[0]=cur->son[1]=null;
		return cur;
	}
	void trans(Node *&pos,int d)
	{
		Node *s=pos->son[d];
		pos->son[d]=s->son[!d];s->son[!d]=pos;
		pos->up(),s->up();
		pos=s;
	}
	int adjust(Node *&pos)
	{
		int d=pos->son[0]->py>pos->son[1]->py;
		if(pos->py>pos->son[d]->py) trans(pos,d),d^=1;
		else d=-1;return d;
	}
	void Insert(Node *&pos,int v)
	{
		if(pos==null) pos=newNode(v);
		else if(pos->v==v) pos->cnt++,pos->up();
		else
		{
			Insert(pos->son[pos->v<v],v),pos->up();
			adjust(pos);
		}
	}
	int Node::LowCount(int v)
	{
		Node *pos=this;int res=0;
		while(pos!=null)
		{
			if(pos->v<v) res+=pos->son[0]->sz+pos->cnt,pos=pos->son[1];
			else pos=pos->son[0];
		}
		return res;
	}
	int Node::Pred(int v)
	{
		Node *pos=this;int res=-INF;
		while(pos!=null)
		{
			if(pos->v<v) chkmx(res,pos->v),pos=pos->son[1];
			else pos=pos->son[0];
		}
		return res;
	}
	int Node::Succ(int v)
	{
		Node *pos=this;int res=INF;
		while(pos!=null)
		{
			if(pos->v>v) chkmn(res,pos->v),pos=pos->son[0];
			else pos=pos->son[1];
		}
		return res;
	}
	void DelNode(Node *&pos)
	{
		int d=adjust(pos);
		if(~d)
		{
			assert(pos!=null);
			DelNode(pos->son[d]),pos->up();
		}
		else pos=null;
	}
	void Delete(Node *&pos,int v)
	{
		if(pos->v==v)
		{
			pos->cnt--,pos->up();
			if(!pos->cnt)
				pos->py=P,DelNode(pos);
		}
		else
		{
			Delete(pos->son[pos->v<v],v),pos->up();
			assert(adjust(pos)==-1);
		}
	}
}
using namespace Treap;
struct Data
{
	int cnt,pred,succ;
	Data(int cnt=0,int pred=-INF,int succ=INF):cnt(cnt),pred(pred),succ(succ){}
}nData;
Data Merge(Data a,Data b){return Data(a.cnt+b.cnt,max(a.pred,b.pred),min(a.succ,b.succ));}
namespace Seg
{
	typedef Treap::Node tNode;
	struct Node
	{
		Node *son[2];
		tNode *treap;
	}*null=new Node,*root=null;int TL,TR;
	Node *newNode()
	{
		static int SIZE=MAXN<<2;
		static Node *ME=(Node*)malloc(SIZE*sizeof(Node)),*cur;
		cur=ME++;cur->son[0]=cur->son[1]=null;cur->treap=Treap::null;
		return cur;
	}
	void Add(Node *&pos,int L,int R,int goal,int v)
	{
		if(pos==null) pos=newNode();
		Insert(pos->treap,v);
		if(L!=R)
		{
			int MID=(L+R)>>1;
			if(goal<=MID) Add(pos->son[0],L,MID,goal,v);
			else Add(pos->son[1],MID+1,R,goal,v);
		}
	}
	Data Access(Node *pos,int L,int R,int l,int r,int v)
	{
		if(L==l && R==r) return Data(pos->treap->LowCount(v),pos->treap->Pred(v),pos->treap->Succ(v));
		else
		{
			int MID=(L+R)>>1;
			if(r<=MID) return Access(pos->son[0],L,MID,l,r,v);
			else if(MID+1<=l) return Access(pos->son[1],MID+1,R,l,r,v);
			else return Merge(Access(pos->son[0],L,MID,l,MID,v),Access(pos->son[1],MID+1,R,MID+1,r,v));
		}
	}
	void Edit(Node *&pos,int L,int R,int goal,int ori,int v)
	{
		Delete(pos->treap,ori);
		Insert(pos->treap,v);
		if(L!=R)
		{
			int MID=(L+R)>>1;
			if(goal<=MID) Edit(pos->son[0],L,MID,goal,ori,v);
			else Edit(pos->son[1],MID+1,R,goal,ori,v);
		}
	}
}
using namespace Seg;
int a[MAXN];
int Kth(int l,int r,int K)
{
	int L=0,R=1e8,res;K--;
	while(L!=R)
	{
		int MID=(L+R+1)>>1;
		if((res=Access(root,TL,TR,l,r,MID).cnt)<=K) L=MID;
		else R=MID-1;
	}
	return L;
}
int main()
{
	freopen("input","r",stdin);
	int n,m;get(n),get(m);TL=1,TR=n;
	for(int i=1;i<=n;i++) get(a[i]),Add(root,TL,TR,i,a[i]);
	for(int i=1;i<=m;i++)
	{
		int opt,pos,l,r,k;
		get(opt);
		if(opt==3) get(pos),get(k);
		else get(l),get(r),get(k);
		switch(opt)
		{
			case 1:put(Access(root,TL,TR,l,r,k).cnt+1);break;
			case 2:put(Kth(l,r,k));break;
			case 3:Edit(root,TL,TR,pos,a[pos],k);a[pos]=k;break;
			case 4:put(Access(root,TL,TR,l,r,k).pred);break;
			case 5:put(Access(root,TL,TR,l,r,k).succ);break;
		}
	}
	flush();
	return 0;
}
/* AC Record(Bugs) *
 * WA trans pushup
 * * * * * * * * * */