记录编号	585457	评测结果	AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
题目名称	[洛谷3950]部落冲突	最终得分	100
用户昵称	┭┮﹏┭┮	是否通过	通过
代码语言	C++	运行时间	6.259 s
提交时间	2023-12-10 12:40:25	内存使用	47.79 MiB

#include <bits/stdc++.h> 
using namespace std;
const int N = 5e5+10;
int n,m;
struct made{
	int ver,nx;
}e[N<<1];
int hd[N],tot,cnt,len;
int fa[N],size[N],son[N],dep[N];
int a[N],top[N],dfn[N],rnk[N];
struct Tree{
	int l,r,la,f;
	#define l(x) t[x].l
	#define r(x) t[x].r
	#define la(x) t[x].la
	#define f(x) t[x].f
}t[N<<2];
void pushup(int x){
	f(x) = f(x<<1) | f(x<<1|1);
}
void pushdown(int x){
	if(la(x) == -1)return;
	la(x<<1) = la(x<<1|1) = la(x);
	f(x<<1) = f(x<<1|1) = la(x);
	la(x) = -1;
}
void build(int x,int l,int r){
	l(x) = l,r(x) = r,la(x) = -1;
	if(l == r)return;
	int mid = l + r >> 1;
	build(x<<1,l,mid);
	build(x<<1|1,mid+1,r);
}
void change(int x,int l,int z){
	if(l(x) == r(x)){
		la(x) = z;
		f(x) = z;
		return; 
	}
	pushdown(x);
	int mid = l(x) + r(x) >> 1;
	if(l <= mid)change(x<<1,l,z);
	else change(x<<1|1,l,z);
	pushup(x);
}
int ask(int x,int l,int r){
	if(l <= l(x) && r(x) <= r)return f(x);
	pushdown(x);
	int mid = l(x) + r(x) >> 1,ans = 0;
	if(l <= mid)ans |= ask(x<<1,l,r);
	if(r > mid)ans |= ask(x<<1|1,l,r);
	return ans;
}
//------------------------------
void add(int x,int y){
	tot++;
	e[tot].ver = y,e[tot].nx = hd[x],hd[x] = tot;
}
void dfs1(int x){
	size[x] = 1;
	for(int i = hd[x];i;i = e[i].nx){
		int y = e[i].ver;
		if(dep[y])continue;
		dep[y] = dep[x] + 1;
		fa[y] = x;
		dfs1(y);
		size[x] += size[y];
		if(!son[x] || size[y] > size[son[x]])son[x] = y;
	}
}
void dfs2(int x,int t){
	dfn[x] = ++cnt;
	rnk[cnt] = x;
	top[x] = t;
	if(!son[x])return;
	dfs2(son[x],t);
	for(int i = hd[x];i;i = e[i].nx){
		int y = e[i].ver;
		if(y != fa[x] && y != son[x])dfs2(y,y);
	}
}
int cal(int x,int y){
	int ans = 0;
	while(top[x] != top[y]){
		if(dep[top[x]] < dep[top[y]])swap(x,y);
		ans |= ask(1,dfn[top[x]],dfn[x]);
		x = fa[top[x]];
	}
	if(x == y)return ans;
	if(dep[x] > dep[y])swap(x,y);
	ans |= ask(1,dfn[x]+1,dfn[y]);
	return ans;
}
int main(){
	freopen("lct.in","r",stdin);
	freopen("lct.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i = 1;i < n;i++){
		int x,y;
		scanf("%d%d",&x,&y);
		add(x,y),add(y,x);
	}
	dep[1] = 1;
	dfs1(1);dfs2(1,1);
	build(1,1,n);
	for(int i = 1;i <= m;i++){
		char c[2];int x,y;
		scanf("%s%d",c,&x);
		if(c[0] == 'U')change(1,dfn[a[x]],0);
		else if(c[0] == 'C'){
			scanf("%d",&y) ;
			x = dep[x] < dep[y]?y:x;
			a[++len] = x;
			change(1,dfn[x],1);
		}
		else{
			scanf("%d",&y);
			int ans = cal(x,y);
			if(ans == 1)printf("No\n");
			else printf("Yes\n");
		}
	}
	
	return 0;
	
}