#include<bits/stdc++.h>

using namespace std;

#define il inline void
#define ll long long
#define lc (tr[x].s[0])
#define rc (tr[x].s[1])
#define int unsigned int
const int N=200000;
struct ios {
    inline char read(){
        static const int IN_LEN=1<<18|1;
        static char buf[IN_LEN],*s,*t;
        return (s==t)&&(t=(s=buf)+fread(buf,1,IN_LEN,stdin)),s==t?-1:*s++;
    }

    template <typename _Tp> inline ios & operator >> (_Tp&x){
        static char c11,boo;
        for(c11=read(),boo=0;!isdigit(c11);c11=read()){
            if(c11==-1)return *this;
            boo|=c11=='-';
        }
        for(x=0;isdigit(c11);c11=read())x=x*10+(c11^'0');
        boo&&(x=-x);
        return *this;
    }
}io;
template<class T>il _print(T x){
	if(x/10) _print(x/10);
	putchar(x%10+'0');
}
template<class T>il print(T x){
	if(x<0) putchar('-'),x=-x;
	_print(x);
}
struct Tr{
	int s[2],p,rev;
}tr[N];
int n,q;
int stk[N];
inline void pushrev(int x)
{
	swap(tr[x].s[0],tr[x].s[1]);
	tr[x].rev^=1;
}
inline void pushdown(int x)
{
	if(tr[x].rev)
	{
		pushrev(lc);
		pushrev(rc);
		tr[x].rev=0;
	}
	return;
}
inline bool isroot(int x)
{
	return tr[tr[x].p].s[0]!=x&&tr[tr[x].p].s[1]!=x;
}
inline void rotato(int x)
{
	int y=tr[x].p,z=tr[y].p;
	int k=tr[y].s[1]==x;
	if(!isroot(y))
	tr[z].s[tr[z].s[1]==y]=x;
	tr[x].p=z;
	tr[y].s[k]=tr[x].s[k^1],tr[tr[x].s[k^1]].p=y;
	tr[x].s[k^1]=y,tr[y].p=x;
	return;
}
inline void splay(int x)
{
	int top=0;
	int r=x;
	stk[++top]=r;
	while(!isroot(r))
	stk[++top]=r=tr[r].p;
	while(top)
	pushdown(stk[top--]);
	while(!isroot(x))
	{
		int y=tr[x].p;
		int z=tr[y].p;
		if(!isroot(y)){
			if((tr[y].s[1]==x)^(tr[z].s[1]==y))
			rotato(x);
			else rotato(y);
		}
		rotato(x);
	}
}
inline void access(int x)
{
	int z=x;
	for(int y=0;x;y=x,x=tr[x].p)
	{
		splay(x);
		tr[x].s[1]=y;
	}
	splay(z);
}
inline void makeroot(int x)
{
	access(x);
	pushrev(x);
}
inline int findroot(int x)
{
	access(x);
	while(tr[x].s[0])
	pushdown(x),x=tr[x].s[0];
	splay(x);
	return x;
}
inline void split(int x,int y)
{
	makeroot(x);
	access(y);
}
inline void link(int x,int y)
{
	makeroot(x);
	if(findroot(y)!=x)
	tr[x].p=y;
}
inline void cut(int x,int y)
{
	makeroot(x);
	if(findroot(y)==x&&tr[y].p==x&&!tr[y].s[0])
	{
		tr[x].s[1]=tr[y].p=0;
	}
	return;
}
signed main()
{
//	freopen("P1501_2.in","r",stdin);
//	freopen("rua.txt","w",stdout);
//	double times=clock(); 
	scanf("%d%d",&n,&q);
	for(int i=1;i<=q;i++)
	{
		char str[7];
		int a,b;
		scanf("%s%d%d",str,&a,&b);
		if(str[0]=='Q')
		{
			makeroot(a);
			if(findroot(b)!=a)
			puts("No");
			else puts("Yes");
		}
		if(str[0]=='C')
		{
			link(a,b);
		}
		if(str[0]=='D')
		{
			cut(a,b);
		}
	}
//	printf("%lf\n",(clock()-times)/1000);
	return 0;
}

第10个点Wa 错误信息为

Wrong Answer. wrong answer Too long on line 37886.