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| # include <bits/stdc++.h>
using namespace std;
const int N = 1e5+7;
/***************************************/
int n,m;
int c[N];
vector<int >G[N];
int fa[N],sz[N],son[N],dep[N];
int dfs1(int u,int f,int d){
fa[u]=f,sz[u]=1,son[u]=0,dep[u]=d;
int gz = G[u].size();
for(int to,i=0;i<gz;i++){
to = G[u][i];
if(to==f) continue;
dfs1(to,u,d+1);
sz[u]+=sz[to];
if(sz[son[u]]<sz[to]) son[u]=to;
}
}
int top[N],tree[N],pre[N],cnt;
int dfs2(int u,int tp){
top[u]=tp,tree[u]=++cnt,pre[tree[u]]=u;
if(son[u]) dfs2(son[u],tp);
int gz = G[u].size();
for(int to,i=0;i<gz;i++){
to = G[u][i];
if(to==fa[u]||to==son[u])continue;
dfs2(to,to);
}
}
int sum[N<<2],lazy[N<<2],lc[N<<2],rc[N<<2];
void pushup(int rt){
sum[rt] = sum[rt<<1]+sum[rt<<1|1]-(rc[rt<<1] == lc[rt<<1|1]);
lc[rt]=lc[rt<<1],rc[rt]=rc[rt<<1|1];
}
void pushdown(int rt){
if(lazy[rt]!=-1){
lazy[rt<<1] = lazy[rt<<1|1] = lazy[rt];
sum [rt<<1] = sum [rt<<1|1] = 1;
lc[rt<<1] = rc[rt<<1] = lazy[rt];
lc[rt<<1|1] = rc[rt<<1|1] = lazy[rt];
lazy[rt]=-1;
}
}
void build(int rt,int l,int r){
if(l==r){
sum[rt]=1,rc[rt]=lc[rt]=c[pre[l]];
return ;
}
int m = (r+l)>>1;
build(rt<<1 ,l ,m);
build(rt<<1|1,m+1,r);
pushup(rt);
}
void update(int rt,int l,int r,int L,int R,int clr){
if(L<=l&&r<=R){
rc[rt]=lc[rt]=lazy[rt]=clr;
sum[rt] = 1;
return ;
}
pushdown(rt);
int m = (r+l)>>1;
if(L<=m) update(rt<<1 ,l ,m,L,R,clr);
if(R> m) update(rt<<1|1,m+1,r,L,R,clr);
pushup(rt);
return ;
}
int query(int rt,int l,int r,int L,int R){
if(L>R) return 0;
if(L<=l&&r<=R) return sum[rt];
pushdown(rt);
int ans = 0,m = (r+l)>>1;
if(R<=m) ans = query(rt<<1 ,l, m,L,R);
else if(L>m) ans = query(rt<<1|1,m+1,r,L,R);
else ans = query(rt<<1 ,l, m,L,R)+
query(rt<<1|1,m+1,r,L,R)-
(rc[rt<<1]==lc[rt<<1|1]);
pushup(rt);
return ans;
}
int query_color(int rt,int l,int r,int pos){
if(l==r) return lc[rt];
pushdown(rt);
int m = (r+l)>>1,ans;
if(pos<=m) ans = query_color(rt<<1 ,l ,m,pos);
else ans = query_color(rt<<1|1,m+1,r,pos);
pushup(rt);
return ans;
}
void init(){
cnt = 0;
for(int i=1;i<=n;i++)G[i].clear();
memset(sum,0,sizeof(sum));
memset(lazy,-1,sizeof(lazy));
};
void brush(int x,int y,int clr){
int fx = top[x],fy = top[y];
while(fx!=fy){
if(dep[fx]<dep[fy]) swap(fx,fy),swap(x,y);
update(1,1,n,tree[fx],tree[x],clr);
x = fa[fx],fx = top[x];
}
if(tree[x]>tree[y]) swap(x,y);
update(1,1,n,tree[x],tree[y],clr);
return ;
}
void solve(int x,int y){
int fx = top[x],fy = top[y];
int ans = 0;
while(fx!=fy){
if(dep[fx]<dep[fy]) swap(fx,fy),swap(x,y);
ans += query(1,1,n,tree[fx],tree[x]);
if(query_color(1,1,n,tree[fa[fx]]) == query_color(1,1,n,tree[fx])) ans--;
x = fa[fx],fx = top[x];
}
if(tree[x]>tree[y]) swap(x,y);
ans += query(1,1,n,tree[x],tree[y]);
printf("%d\n",ans);
return ;
}
int main(){
while(~scanf("%d%d",&n,&m)){
init();
for(int i=1;i<=n;i++) scanf("%d",&c[i]);
for(int i=2,u,v;i<=n;i++){
scanf("%d %d",&u,&v);
G[u].push_back(v);
G[v].push_back(u);
}
dfs1(1,-1,1);
dfs2(1,1);
build(1,1,n);
int l,r,x;
char a[10];
while(m--){
scanf("%s",a);
scanf("%d %d",&l,&r);
if(a[0]=='C'){
scanf("%d",&x);
brush(l,r,x);
}
else solve(l,r);
}
}
return 0;
}
|
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