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| #include<queue> #include<cstdio> #include<cstring> #include<algorithm> using namespace std;
typedef pair<int,int> pii; const int N=1e5+10;
struct GRAPH{ int head[N<<1],nxt[N<<2],to[N<<2],ncnt; void AddEdge(int u,int v){ int p=++ncnt,q=++ncnt; nxt[p]=head[u],to[p]=v,head[u]=p; nxt[q]=head[v],to[q]=u,head[v]=q; } int operator [](const int &u){return head[u];} }; GRAPH Gr,Rst;
struct STACK{ int ary[N],ntop; void Push(int x){ary[++ntop]=x;} void Pop(){ary[ntop--]=0;} int Top(){return ary[ntop];} }St;
int n,m,ndfn,npnt; int val[N<<1],low[N]; int dfn[N<<1],tp[N<<1],wei[N<<1],anc[N<<1],dep[N<<1],siz[N<<1],idfn[N<<1]; priority_queue< pii,vector<pii>,greater<pii> > smn[N];
inline int Ri(){ register int r=0,c=getchar(); while(c<'0' || '9'<c) c=getchar(); while('0'<=c && c<='9') r=(r<<1)+(r<<3)+c-'0',c=getchar(); return r; } inline char Rc(){ register int c=getchar(); while(c!='A' && c!='C') c=getchar(); return (char)c; } void Tarjan(int u){ dfn[u]=low[u]=++ndfn; St.Push(u); for(int it=Gr[u];it;it=Gr.nxt[it]){ int v=Gr.to[it]; if(dfn[v]){low[u]=min(low[u],dfn[v]);continue;} Tarjan(v); low[u]=min(low[u],low[v]); if(low[v]==dfn[u]){ npnt++; Rst.AddEdge(npnt,u); for(int tmp=-1;tmp!=v;St.Pop()) Rst.AddEdge(npnt,tmp=St.Top()); } } } void DFS1(int u,int fa){ siz[u]=1,anc[u]=fa,dep[u]=dep[fa]+1; for(int it=Rst[u];it;it=Rst.nxt[it]){ int v=Rst.to[it]; if(v==fa) continue; if(u>n){ val[u]=min(val[u],val[v]); smn[u-n].push(make_pair(val[v],v)); } DFS1(v,u); siz[u]+=siz[v]; if(siz[v]>siz[wei[u]]) wei[u]=v; } } void DFS2(int u,int tp_){ idfn[dfn[u]=++ndfn]=u,tp[u]=tp_; if(wei[u]) DFS2(wei[u],tp_); else return; for(int it=Rst[u];it;it=Rst.nxt[it]){ int v=Rst.to[it]; if(v==wei[u] || v==anc[u]) continue; DFS2(v,v); } } struct SEGTREE{ int mn[N<<2]; #define idx(l,r) (((l)!=(r))|((l)+(r))) void Build(int le,int ri){ if(le==ri){ mn[idx(le,ri)]=val[idfn[le]]; return; } int mi=(le+ri)>>1; Build(le,mi),Build(mi+1,ri); PushUp(le,ri); } void PushUp(int le,int ri){ int mi=(le+ri)>>1; mn[idx(le,ri)]=min(mn[idx(le,mi)],mn[idx(mi+1,ri)]); } void Modify(int le,int ri,int po,int key){ if(le==ri){ mn[idx(le,ri)]=key; return; } int mi=(le+ri)>>1; if(po<=mi) Modify(le,mi,po,key); else Modify(mi+1,ri,po,key); PushUp(le,ri); } int Query(int le,int ri,int Le,int Ri){ if(Le<=le && ri<=Ri) return mn[idx(le,ri)]; int mi=(le+ri)>>1; if(Ri<=mi) return Query(le,mi,Le,Ri); if(mi<Le) return Query(mi+1,ri,Le,Ri); return min(Query(le,mi,Le,Ri),Query(mi+1,ri,Le,Ri)); } }Se; pair<int,int> MQuery(int u,int v){ //<LCA,min> int rmn=1e9+10; while(tp[u]!=tp[v]){ if(dep[tp[u]]<dep[tp[v]]) swap(u,v); rmn=min(rmn,Se.Query(1,ndfn,dfn[tp[u]],dfn[u])); u=anc[tp[u]]; } if(dep[u]>dep[v]) swap(u,v); rmn=min(rmn,Se.Query(1,ndfn,dfn[u],dfn[v])); return make_pair(u,rmn); } int main(){ npnt=n=Ri(),m=Ri(); int cas=Ri(); memset(val,0x3f,sizeof val); for(int i=1;i<=n;i++) val[i]=Ri(); for(int i=1;i<=m;i++) Gr.AddEdge(Ri(),Ri()); Tarjan(1); memset(dfn,0,sizeof dfn); DFS1(1,0); ndfn=0,DFS2(1,1); Se.Build(1,ndfn); while(cas--){ char cmd=Rc(); int u=Ri(),v=Ri(); if(cmd=='A'){ pair<int,int> res=MQuery(u,v); int lca=res.first; if(lca>n) res.second=min(res.second,val[anc[lca]]); printf("%d\n",res.second); } else{ val[u]=v; if(anc[u]>n){ int fa=anc[u]-n; while(!smn[fa].empty() && smn[fa].top().first!=val[smn[fa].top().second]) smn[fa].pop(); smn[fa].push(make_pair(val[u],u)); Se.Modify(1,ndfn,dfn[fa+n],smn[fa].top().first); } Se.Modify(1,ndfn,dfn[u],val[u]); } } return 0; }
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