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| #include<iostream>
#include<cstdio>
#include<cstring>
#include<cctype>
#include<algorithm>
#include<cmath>
#include<set>
using namespace std;
inline int read(){
int w=0,x=0;char c=getchar();
while(!isdigit(c))w|=c=='-',c=getchar();
while(isdigit(c))x=(x<<3)+(x<<1)+(c^48),c=getchar();
return w?-x:x;
}
namespace star
{
const int maxn=2e5+10,INF=0x3f3f3f3f;
int n,m,Q,a[maxn],cnt;
struct gragh{
int ecnt,head[maxn],to[maxn<<1],nxt[maxn<<1];
inline void addedge(int a,int b){
to[++ecnt]=b,nxt[ecnt]=head[a],head[a]=ecnt;
to[++ecnt]=a,nxt[ecnt]=head[b],head[b]=ecnt;
}
}G1,G2;
int st[maxn],dfn[maxn],tot,id[maxn];
struct SegmentTree{
#define ls (ro<<1)
#define rs (ro<<1|1)
#define mid ((l+r)>>1)
int mn[maxn<<2];
inline void pushup(const int &ro){
mn[ro]=min(mn[ls],mn[rs]);
}
void build(const int& ro=1,const int &l=1,const int &r=cnt){
if(l==r) return mn[ro]=a[id[l]],void();
build(ls,l,mid);build(rs,mid+1,r);
pushup(ro);
}
void update(const int &x,const int &ro=1,const int &l=1,const int &r=cnt){
if(l==r) return mn[ro]=a[id[l]],void();
if(x<=mid) update(x,ls,l,mid);
else update(x,rs,mid+1,r);
pushup(ro);
}
int query(const int &x,const int &y,const int &ro=1,const int &l=1,const int &r=cnt){
if(x==l and y==r) return mn[ro];
if(y<=mid) return query(x,y,ls,l,mid);
else if(x>mid) return query(x,y,rs,mid+1,r);
else return min(query(x,mid,ls,l,mid),query(mid+1,y,rs,mid+1,r));
}
#undef ls
#undef rs
#undef mid
}T;
void tarjan(int x){
dfn[x]=id[x]=++tot;
st[++st[0]]=x;
for(int i=G1.head[x];i;i=G1.nxt[i]){
int u=G1.to[i];
if(!dfn[u]){
tarjan(u);
id[x]=min(id[x],id[u]);
if(id[u]>=dfn[x]){
cnt++;
int now=-1;
G2.addedge(x,cnt);
while(now^u) now=st[st[0]--],G2.addedge(now,cnt);
}
}else id[x]=min(id[x],dfn[u]);
}
}
int dep[maxn],siz[maxn],fa[maxn],son[maxn],top[maxn];
multiset<int> q[maxn];
void dfs1(int x,int f){
fa[x]=f,dep[x]=dep[f]+1,siz[x]=1;
for(int i=G2.head[x];i;i=G2.nxt[i]){
int u=G2.to[i];
if(u==f)continue;
dfs1(u,x);
if(x>n) q[x-n].insert(a[u]);
siz[x]+=siz[u];
if(siz[u]>siz[son[x]])son[x]=u;
}
if(x>n) a[x]=*q[x-n].begin();
}
void dfs2(int x,int topf){
top[x]=topf,dfn[x]=++tot,id[tot]=x;
if(!son[x])return;
dfs2(son[x],topf);
for(int i=G2.head[x];i;i=G2.nxt[i]){
int u=G2.to[i];
if(u==fa[x] or u==son[x])continue;
dfs2(u,u);
}
}
inline int LCA(int x,int y){
int ans=INF;
while(top[x]!=top[y]){
if(dep[top[x]]<dep[top[y]]) swap(x,y);
ans=min(ans,T.query(dfn[top[x]],dfn[x]));
x=fa[top[x]];
}
if(dep[x]<dep[y])swap(x,y);
ans=min(ans,T.query(dfn[y],dfn[x]));
if(y>n) ans=min(ans,a[fa[y]]);
return ans;
}
inline bool gc(){
char c=getchar();
while(!isalpha(c))c=getchar();
return c=='C';
}
inline void work(){
n=cnt=read(),m=read(),Q=read();
for(int i=1;i<=n;i++) a[i]=read();
for(int i=1;i<=m;i++) G1.addedge(read(),read());
tarjan(1);
tot=0;
dfs1(1,0);
dfs2(1,1);
T.build();
while(Q--)
if(gc()){
int x=read(),w=read(),u=fa[x];
if(u)
q[u-n].erase(q[u-n].find(a[x])),
q[u-n].insert(w),
a[u]=*q[u-n].begin(),
T.update(dfn[u]);
a[x]=w;
T.update(dfn[x]);
}else printf("%d\n",LCA(read(),read()));
}
}
signed main(){
star::work();
return 0;
}
|
