bzoj3673【主席樹】

好久沒寫主席樹啦

雖然是可持久化並查集，但是直接用一個主席樹維護一下father數組就好啦

居然1A好開心

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cstring>
using namespace std;
typedef long long LL;
inline int read()
{
	int x=0;bool f=0;char c=getchar();
	for (;c<'0'||c>'9';c=getchar()) f=c=='-'?1:0;
	for (;c>='0'&&c<='9';c=getchar()) x=x*10+c-'0';
	return f?-x:x;
}
const int N=20010,M=150000;
int n,m;
struct na
{
	na *ch[2];
	int val;
	int getv(int x,int l,int r);
	na* update(int x,int a,int l,int r);
}P[M],*sz=P,*nul,*tr[N],*now;

int na::getv(int x,int l,int r)
{
	if (l==r) return this->val;
	if (x<=(l+r>>1)) return this->ch[0]->getv(x,l,l+r>>1);
	else return this->ch[1]->getv(x,(l+r>>1)+1,r);
}

inline na* newnode()
{
	sz->ch[0]=sz->ch[1]=nul;
	return sz++;
}

na* na::update(int x,int a,int l,int r)
{
	na *rec=newnode();
	if (l==r) {rec->val=a;return rec;}
	if (x<=(l+r>>1)) rec->ch[1]=this->ch[1],rec->ch[0]=this->ch[0]->update(x,a,l,l+r>>1);
	else rec->ch[0]=this->ch[0],rec->ch[1]=this->ch[1]->update(x,a,(l+r>>1)+1,r);
	return rec;
}

na* build(int l,int r)
{
	na *rec=newnode();
	if (l==r) {rec->val=l;return rec;}
	rec->ch[0]=build(l,l+r>>1);
	rec->ch[1]=build((l+r>>1)+1,r);
	return rec;
}

inline int find(int x)
{
	for (int fx;fx=now->getv(x,1,n),fx!=x;x=fx);
	return x;
}

int main()
{
	nul=newnode();
	n=read();m=read();
	now=tr[0]=build(1,n);
	for (int i=1,op,a,b;i<=m;i++)
	{
		op=read();a=read();
		if (op==1)
		{
			b=read();
			a=find(a);b=find(b);
			if (a!=b) now=now->update(a,b,1,n);
		}
		else if (op==2)
			now=tr[a];
		else
		{
			b=read();
			a=find(a);b=find(b);
			printf("%d\n",(int)a==b);
		}
		tr[i]=now;
	}
	return 0;
}