原题传送门
这题用Link-Cut-Tree解决,Link-Cut-Tree详解
我不太会踩爆Link-Cut-Tree的并查集做法qaq
我们用Link-Cut-Tree维护连通性(十分无脑)
Connect操作:把u,v两个点连起来
Destroy操作:把u,v两个点分开来
Query操作:判断在这个森林里u的根和v的根是否相等
#include <bits/stdc++.h>
#define N 10005
using namespace std;
inline int read()
{
register int f=1,x=0;register char ch;
do{ch=getchar();if(ch=='-')f=-1;}while(ch<'0'||ch>'9');
do{x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}while(ch>='0'&&ch<='9');
return f*x;
}
inline void Swap(register int &a,register int &b)
{
a^=b^=a^=b;
}
struct Link_Cut_Tree{
int c[N][2],fa[N],top,q[N],rev[N];
inline void pushdown(register int x){
if(rev[x])
{
register int l=c[x][0],r=c[x][1];
rev[l]^=1,rev[r]^=1,rev[x]^=1;
Swap(c[x][0],c[x][1]);
}
}
inline bool isroot(register int x)
{
return c[fa[x]][0]!=x&&c[fa[x]][1]!=x;
}
inline void rotate(register int x)
{
int y=fa[x],z=fa[y],l,r;
l=c[y][0]==x?0:1;
r=l^1;
if(!isroot(y))
c[z][c[z][0]==y?0:1]=x;
fa[x]=z;
fa[y]=x;
fa[c[x][r]]=y;
c[y][l]=c[x][r];
c[x][r]=y;
}
inline void splay(register int x)
{
top=1;
q[top]=x;
for(register int i=x;!isroot(i);i=fa[i])
q[++top]=fa[i];
for(register int i=top;i;--i)
pushdown(q[i]);
while(!isroot(x))
{
int y=fa[x],z=fa[y];
if(!isroot(y))
rotate((c[y][0]==x)^(c[z][0]==y)?(x):(y));
rotate(x);
}
}
inline void access(register int x)
{
for(register int t=0;x;t=x,x=fa[x])
{
splay(x);
c[x][1]=t;
}
}
inline void makeroot(register int x)
{
access(x);
splay(x);
rev[x]^=1;
}
inline int findroot(register int x)
{
access(x);
splay(x);
while(c[x][0])
x=c[x][0];
return x;
}
inline void split(register int x,register int y)
{
makeroot(x);
access(y);
splay(y);
}
inline void cut(register int x,register int y)
{
split(x,y);
c[y][0]=0;
fa[x]=0;
}
inline void link(register int x,register int y)
{
makeroot(x);
fa[x]=y;
}
}T;
int n,m;
int main()
{
n=read(),m=read();
char ch[10];
while(m--)
{
scanf("%s",ch);
if(ch[0]=='C')
{
int x=read(),y=read();
T.link(x,y);
}
else if(ch[0]=='D')
{
int x=read(),y=read();
T.cut(x,y);
}
else
{
int x=read(),y=read();
puts(T.findroot(x)==T.findroot(y)?"Yes":"No");
}
}
return 0;
}
原文地址:https://www.cnblogs.com/yzhang-rp-inf/p/10203159.html
时间: 2024-11-04 05:04:48