3123: [Sdoi2013]森林 主席树+启发式合并+LCA

for (int i=1;i<=16;i++)
fa[x][i]=fa[fa[x][i-1]][i-1];

for (int i=1;(1<<i)<=deep[x];i++)
fa[x][i]=fa[fa[x][i-1]][i-1];

#include<iostream>
#include<cstdio>
#include<algorithm>
#define N 80005
#define M 10000005
using namespace std;
int n,m,T,ans,cnt,tot,sz,testcase,query_sum;
int f
,size
,deep
,v
,num
,hash
,root
,fa
[17];
int ls[M],rs[M],sum[M];
int head
,list[N<<1],next[N<<1];
inline int read()
{
int a=0,f=1; char c=getchar();
while (c<'0'||c>'9') {if (c=='-') f=-1; c=getchar();}
while (c>='0'&&c<='9') {a=a*10+c-'0'; c=getchar();}
return a*f;
}
inline int Find(int x)
{
int l=1,r=tot;
while (l<=r)
{
int mid=l+r>>1;
if (hash[mid]==x) return mid;
else if (hash[mid]<x) l=mid+1;
else r=mid-1;
}
}
inline int insert(int x,int y)
{
next[++cnt]=head[x];
head[x]=cnt;
list[cnt]=y;
}
int find(int i)
{
if (!f[i]) size[i]=1,f[i]=i;
if (f[i]==i) return i;
return f[i]=find(f[i]);
}
inline void Union(int x,int y)
{
int p=find(x),q=find(y);
f[p]=q; size[q]+=size[p];
}
void update(int l,int r,int x,int &y,int val)
{
y=++sz;
ls[y]=ls[x]; rs[y]=rs[x]; sum[y]=sum[x]+1;
if (l==r) return;
int mid=l+r>>1;
if (val<=mid) update(l,mid,ls[x],ls[y],val);
else update(mid+1,r,rs[x],rs[y],val);
}
void dfs(int x)
{
for (int i=1;i<=16;i++)
fa[x][i]=fa[fa[x][i-1]][i-1];
update(1,tot,root[fa[x][0]],root[x],Find(v[x]));
for (int i=head[x];i;i=next[i])
if (list[i]!=fa[x][0])
{
fa[list[i]][0]=x;
deep[list[i]]=deep[x]+1;
dfs(list[i]);
}
}
inline int lca(int x,int y)
{
if (deep[x]<deep[y]) swap(x,y);
int t=deep[x]-deep[y];
for (int i=0;(1<<i)<=t;i++)
if ((1<<i)&t) x=fa[x][i];
for (int i=16;~i;i--)
if (fa[x][i]!=fa[y][i]) x=fa[x][i],y=fa[y][i];
return x==y?x:fa[x][0];
}
inline int query(int a,int b,int c,int d,int k)
{
int l=1,r=tot;
while (l!=r)
{
int mid=l+r>>1;
int tmp=sum[ls[a]]+sum[ls[b]]-sum[ls[c]]-sum[ls[d]];
if (tmp>=k) r=mid,a=ls[a],b=ls[b],c=ls[c],d=ls[d];
else l=mid+1,a=rs[a],b=rs[b],c=rs[c],d=rs[d],k-=tmp;
}
return l;
}
int main()
{
//  freopen("rforest.in","r",stdin);
//  freopen("rforest.out","w",stdout);

testcase=read();
n=read(); m=read(); T=read();
for (int i=1;i<=n;i++) v[i]=num[i]=read();
sort(num+1,num+n+1);
hash[++tot]=num[1];
for (int i=2;i<=n;i++)
if (num[i]!=num[i-1]) hash[++tot]=num[i];
for (int i=1;i<=m;i++)
{
int u=read(),v=read();
insert(u,v); insert(v,u); Union(u,v);
}
for (int i=1;i<=n;i++)
if (!fa[i][0]) dfs(i);
while (T--)
{
char opt[5];
scanf("%s",opt);
int a=read()^ans,b=read()^ans,k;
if (opt[0]=='Q')
{
query_sum++;
k=read()^ans;
int c=lca(a,b);
int d=fa[c][0];
printf("%d\n",ans=hash[query(root[a],root[b],root[c],root[d],k)]);
}
else
{
int p=find(a),q=find(b);
if (size[p]>size[q]) swap(a,b);
fa[a][0]=b; deep[a]=deep[b]+1;
dfs(a);
Union(a,b);
insert(a,b); insert(b,a);
}
}
return 0;
}