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| #include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define Ls (v<<1)
#define Rs ((v<<1)|1)
#define fpos fpos233
using namespace std;
struct Node
{
int Lval,Rval,ans;
inline Node():Lval(0),Rval(0),ans(0){}
inline Node(int val):Lval(val),Rval(val),ans(1){}
};
struct Tree
{
int L,R,lazy;
Node Lval,Rval;
}T[400005];
struct Edge
{
int to,next;
}e[200005];
int a[100005],d[100005],h[100005],pre[100005],siz[100005],vson[100005],top[100005],pos[100005],fpos[100005],cnt,sign;
inline void Addedge(int x,int y)
{
e[++cnt]=(Edge){y,h[x]};h[x]=cnt;return;
}
inline void dfs1(int x,int dep)
{
int i,y;
d[x]=dep;siz[x]=1;
vson[x]=-1;
for(i=h[x];i;i=e[i].next)
{
y=e[i].to;
if(y==pre[x])continue;
pre[y]=x;
dfs1(y,dep+1);
siz[x]+=siz[y];
if(vson[x]==-1||siz[vson[x]]<siz[y])vson[x]=y;
}
return;
}
inline void dfs2(int x,int sp)
{
int i,y;
pos[x]=++sign;top[x]=sp;
fpos[sign]=x;
if(vson[x]!=-1)dfs2(vson[x],sp);
for(i=h[x];i;i=e[i].next)
{
y=e[i].to;
if(y==pre[x]||y==vson[x])continue;
dfs2(y,y);
}
return;
}
inline Node operator+(const Node& a,const Node& b)
{
Node ans;
ans.Lval=a.Lval;
ans.Rval=b.Rval;
ans.ans=a.ans+b.ans-(a.Rval==b.Lval);
return ans;
}
inline void pushup(int v)
{
T[v].Lval=T[Ls].Lval+T[Rs].Lval;
T[v].Rval=T[Rs].Rval+T[Ls].Rval;
return;
}
inline void pushdown(int v)
{
if(!T[v].lazy)return;
T[Ls].Lval=T[Ls].Rval=T[Rs].Lval=T[Rs].Rval=Node(T[v].lazy);
T[Ls].lazy=T[Rs].lazy=T[v].lazy;
T[v].lazy=0;
return;
}
inline void Build(int L,int R,int v)
{
T[v].L=L;T[v].R=R;
if(L==R)
{
T[v].Lval=T[v].Rval=Node(a[fpos[L]]);
return;
}
int mid=(L+R)>>1;
Build(L,mid,Ls);
Build(mid+1,R,Rs);
pushup(v);
return;
}
inline void Modify(int L,int R,int val,int v)
{
if(L>T[v].R||R<T[v].L)return;
if(L<=T[v].L&&R>=T[v].R)
{
T[v].Lval=T[v].Rval=Node(val);
T[v].lazy=val;
return;
}
pushdown(v);
Modify(L,R,val,Ls);
Modify(L,R,val,Rs);
pushup(v);
return;
}
inline Node QueryL(int L,int R,int v)
{
if(L==T[v].L&&R==T[v].R)return T[v].Lval;
int mid=(T[v].L+T[v].R)>>1;
pushdown(v);
if(R<=mid)return QueryL(L,R,Ls);
if(L>mid)return QueryL(L,R,Rs);
return QueryL(L,mid,Ls)+QueryL(mid+1,R,Rs);
}
inline Node QueryR(int L,int R,int v)
{
if(L==T[v].L&&R==T[v].R)return T[v].Rval;
int mid=(T[v].L+T[v].R)>>1;
pushdown(v);
if(R<=mid)return QueryR(L,R,Ls);
if(L>mid)return QueryR(L,R,Rs);
return QueryR(mid+1,R,Rs)+QueryR(L,mid,Ls);
}
inline void Modify(int x,int y,int val)
{
while(top[x]!=top[y])
{
if(d[top[x]]<d[top[y]])swap(x,y);
Modify(pos[top[x]],pos[x],val,1);
x=pre[top[x]];
}
if(d[x]>d[y])swap(x,y);
Modify(pos[x],pos[y],val,1);
return;
}
inline Node Query(int x,int y)
{
Node ansL,ansR;
while(top[x]!=top[y])
{
if(d[top[x]]>=d[top[y]])
{
ansL=ansL+QueryR(pos[top[x]],pos[x],1);
x=pre[top[x]];
}
else
{
ansR=QueryL(pos[top[y]],pos[y],1)+ansR;
y=pre[top[y]];
}
}
if(d[x]>d[y])return ansL+QueryR(pos[y],pos[x],1)+ansR;
return ansL+QueryL(pos[x],pos[y],1)+ansR;
}
int main(void)
{
int siz=40<<20;
__asm__ ("movq %0,%%rsp\n"::"r"((char*)malloc(siz)+siz));
int i,n,m,x,y,v,ch;
scanf("%d%d",&n,&m);
for(i=1;i<=n;++i)scanf("%d",&a[i]);
for(i=1;i<n;++i)
{
scanf("%d%d",&x,&y);
Addedge(x,y);
Addedge(y,x);
}
dfs1(1,1);
dfs2(1,1);
Build(1,sign,1);
for(i=1;i<=m;++i)
{
while(ch=getchar())if(ch=='C'||ch=='Q')break;
scanf("%d%d",&x,&y);
if(ch=='C')
{
scanf("%d",&v);Modify(x,y,v);
}
else printf("%d\n",Query(x,y).ans);
}
exit(0);
}
|