题目 P3313，同题在loj加上Ofast和火车头能过，现在洛谷的最快记录是 2.28s，真的不会卡了，谁能帮个忙吗，感谢！

#include <iostream>
#include <vector>
#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)>(b)?(a):(b))
#define swap(a,b) ((a)^=(b)^=(a)^=(b))
char *p1, *p2, buf[55];
#define getchar() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 55, stdin), p1 == p2) ? EOF : *p1 ++ )
int read(){
	int res=0,f=1;char c=getchar();
	while (!isdigit(c)) {if (c=='-') f=-1;c=getchar();}
	while (isdigit(c)) {res=(res<<1)+(res<<3)+(c^48);c=getchar();}
	return res*f;
}
void write(int x){
	if (x<0) putchar('-'),x=-x;
	if (x>9) write(x/10);
	putchar(x%10+48);
}
const int N=2e5+5,SN=605;
int n,q,dep[N],siz[N],fa[N],son[N];
std::vector<int>e[N];
void dfs(int u,int father){
	dep[u]=dep[father]+1;
	fa[u]=father;
	siz[u]=1;
	int maxn=-1;
	for (auto v:e[u]){
		if (v==father) continue;
		dfs(v,u),siz[u]+=siz[v];
		if (siz[v]>maxn) maxn=siz[v],son[u]=v;
	}
}
int dfn[N],top[N],tip=1;
void dfs2(int u,int father,int op){
	if (op) top[u]=top[father];
	dfn[u]=tip++;
	if (son[u]) dfs2(son[u],u,1);
	for (auto v:e[u]){
		if (v==father||v==son[u]) continue;
		dfs2(v,u,0);
	}
}
void init(int root){
	dfs(root,0);
	for (register int i=1;i<=n;i++) top[i]=i;
	dfs2(root,0,0);
}
int _c[N],_w[N],c[N],w[N];
struct block_array{
	#define lc(x) ((x)*val-val+1)
	#define rc(x) (min(n,(x)*val))
	int val,block[N],sum[N][SN],mx[N][SN];
	void build(){
		val=141;
		for (register int i=1;i<=n;i++){
			block[i]=(n-1)/val+1,mx[c[i]][block[i]]=-1e9;
			sum[c[i]][block[i]]+=w[i];
			mx[c[i]][block[i]]=max(mx[c[i]][block[i]],w[i]);
		}
	}
	void cc(int x,int k){
		sum[c[x]][block[x]]-=w[x];
		sum[k][block[x]]+=w[x];
		mx[c[x]][block[x]]=-1e9;
		for (register int i=lc(block[x]);i<=rc(block[x]);i++)
			if (i!=x) mx[c[i]][block[i]]=max(mx[c[i]][block[i]],w[i]);
		mx[k][block[x]]=max(mx[k][block[x]],w[x]);
		c[x]=k;
	}
	void cw(int x,int k){
		sum[c[x]][block[x]]+=k-w[x];
		w[x]=k;
		mx[c[x]][block[x]]=-1e9;
		for (register int i=lc(block[x]);i<=rc(block[x]);i++)
			mx[c[i]][block[i]]=max(mx[c[i]][block[i]],w[i]);
	}
	int qs(int l,int r,int k){
//		cout<<l<<' '<<r<<' '<<k<<'\n';
		int res=0;
		if (block[l]==block[r]){
			for (register int i=l;i<=r;i++) res+=(c[i]==k)*w[i];
			return res;
		}
		for (register int i=l;i<=rc(block[l]);i++) res+=(c[i]==k)*w[i];
		for (register int i=r;i>=lc(block[r]);i--) res+=(c[i]==k)*w[i];
		for (register int i=block[l]+1;i<block[r];i++) res+=sum[k][i];
		return res;
	}
	int qm(int l,int r,int k){
		int res=-1e9;
		if (block[l]==block[r]){
			for (register int i=l;i<=r;i++) if (c[i]==k) res=max(res,w[i]);
			return res;
		}
		for (register int i=l;i<=rc(block[l]);i++) if (c[i]==k) res=max(res,w[i]);
		for (register int i=r;i>=lc(block[r]);i--) if (c[i]==k) res=max(res,w[i]);
		for (register int i=block[l]+1;i<block[r];i++) res=max(res,mx[k][i]);
		return res;
	}
	#undef lc
	#undef rc
}book;
int QS(int x,int y,int k){
	int res=0;
	while (top[x]!=top[y]){
		if (dep[top[x]]<dep[top[y]]) swap(x,y);
		res+=book.qs(dfn[top[x]],dfn[x],k);
		x=fa[top[x]];
	}
	if (dep[x]>dep[y]) swap(x,y);
	res+=book.qs(dfn[x],dfn[y],k);
	return res;
}
int QM(int x,int y,int k){
	int res=-1e9;
	while (top[x]!=top[y]){
		if (dep[top[x]]<dep[top[y]]) swap(x,y);
		res=max(res,book.qm(dfn[top[x]],dfn[x],k));
		x=fa[top[x]];
	}
	if (dep[x]>dep[y]) swap(x,y);
	res=max(res,book.qm(dfn[x],dfn[y],k));
	return res;
}
signed main(){
//	freopen("1.in","r",stdin);
//	freopen("1.out","w",stdout);
	n=read(),q=read();
	for (register int i=1;i<=n;i++){
		_w[i]=read();
		_c[i]=read();
	}
	for (register int i=1;i<n;i++){
		int u=read(),v=read();
		e[u].push_back(v);
		e[v].push_back(u);
	}
	init(1);
	for (register int i=1;i<=n;i++){
		c[dfn[i]]=_c[i];
		w[dfn[i]]=_w[i];
	}
//	for (int i=1;i<=n;i++) cout<<c[i]<<' ';cout<<'\n';
//	for (int i=1;i<=n;i++) cout<<w[i]<<' ';cout<<'\n';
	book.build();
	while (q--){
		char c1=getchar(),c2;
		while (c1!='C'&&c1!='Q') c1=getchar();c2=getchar();
		while (c2!='C'&&c2!='W'&&c2!='S'&&c2!='M') c2=getchar();
		int x=read(),y=read();
		if (c1=='C'&&c2=='C') _c[x]=y,book.cc(dfn[x],y);
		if (c1=='C'&&c2=='W') _w[x]=y,book.cw(dfn[x],y);
		if (c1=='Q'&&c2=='S') printf("%d\n",QS(x,y,_c[x]));
		if (c1=='Q'&&c2=='M') printf("%d\n",QM(x,y,_c[x]));
	}
	return 0;
}