[Sdoi2008]Cave 洞穴勘测

BZOJ好了以后去交了这题,算是动态树补完

题目大意:

求一棵树上任意两点的连通性


这道题算是真真正正的link-cut tree了,之前的动态树题目都没有涉及link和cut操作

所以这道题让我发现了我在写cut过程中的一个错误,也让我更加深刻的体会到了link-cut tree的优美


对于修改,link cut即可

对于每个询问,看他们是否在同一棵树中


code:

//Lib
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<ctime>

#include<iostream>
#include<algorithm>
#include<vector>
#include<string>
#include<queue>
using namespace std;
//Macro
#define rep(i,a,b) for(int i=a,tt=b;i<=tt;++i)
#define rrep(i,a,b) for(int i=a,tt=b;i>=tt;--i)
#define erep(i,e,x) for(int i=x;i;i=e[i].next)
#define irep(i,x) for(__typedef(x.begin()) i=x.begin();i!=x.end();i++)
#define read() (strtol(ipos,&ipos,10))
#define sqr(x) ((x)*(x))
#define pb push_back
#define PS system("pause");
typedef long long ll;
typedef pair<int,int> pii;
const int oo=~0U>>1;
const double inf=1e20;
const double eps=1e-6;
string name="",in=".in",out=".out";
//Var
struct T
{
	int LC,RC,FA;
	bool REV;
	#define lc(x) tree[x].LC
	#define rc(x) tree[x].RC
	#define fa(x) tree[x].FA
	#define rev(x) tree[x].REV
}tree[10008];
int n,m;
void Update(int x)
{
	if(rev(x))
	{
		swap(lc(x),rc(x));rev(x)^=1;
		rev(lc(x))^=1;rev(rc(x))^=1;
	}
}
void Zig(int x)
{
	int y=fa(x),z=fa(y);
	if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;
	fa(rc(x))=y;lc(y)=rc(x);fa(y)=x;rc(x)=y;
	Update(y);
}
void Zag(int x)
{
	int y=fa(x),z=fa(y);
	if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;
	fa(lc(x))=y;rc(y)=lc(x);fa(y)=x;lc(x)=y;
	Update(y);
}
bool isRoot(int x){return lc(fa(x))!=x&&rc(fa(x))!=x;}
void Push_Down(int x){if(!isRoot(x))Push_Down(fa(x));Update(x);}
void Splay(int x)
{
	Push_Down(x);
	for(int y,z;!isRoot(x);)
	{
		y=fa(x);z=fa(y);
		if(isRoot(y))
			if(lc(y)==x)Zig(x);
			else Zag(x);
		else
			if(lc(z)==y)
				if(lc(y)==x)Zig(y),Zig(x);
				else Zag(x),Zig(x);
			else
				if(rc(y)==x)Zag(y),Zag(x);
				else Zig(x),Zag(x);
	}
	Update(x);
}
void Expose(int x){for(int y=0;x;x=fa(x)){Splay(x);rc(x)=y;Update(x);y=x;}}
void Evert(int x){Expose(x);Splay(x);rev(x)^=1;}
void Link(int x,int y){Evert(x);fa(x)=y;}
void Cut(int x,int y){Expose(y);Splay(x);if(fa(x)==y)fa(x)=0;else{Expose(x);Splay(y);fa(y)=0;}}
bool Query(int a,int b)
{
	int x=a,y=b;
	Expose(y);
	for(y=0;x;x=fa(x)){Splay(x);if(!fa(x))break;y=x;}
	for(;rc(x);x=rc(x));
	return x==b;
}
void Work()
{
	int a,b;char ch[10];
	rep(i,1,m)
	{
		scanf("%s%d%d",ch,&a,&b);
		if(ch[0]=='C')Link(a,b);
		if(ch[0]=='D')Cut(a,b);
		if(ch[0]=='Q')puts(Query(a,b)?"Yes":"No");
	}
}
int main()
{
//	freopen((name+in).c_str(),"r",stdin);
//	freopen((name+out).c_str(),"w",stdout);
	scanf("%d%d",&n,&m);	
	Work();
	return 0;
}


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