【BZOJ 3123】[Sdoi2013]森林 启发式合并主席树

//如题#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#define maxn 500020using namespace std;int read(){char c=getchar();int f=1,x=0;for(;c>'9'||c<'0';c=getchar())if(c=='-')f=-1;for(;c<='9'&&c>='0';c=getchar())x=x*10+c-'0';return x*f;}int n,m,cl,T,ls[maxn*20],rs[maxn*20],s[maxn*20],rt[maxn],t[maxn],val[maxn];int num,head[maxn],tot=1,nn,f[maxn][20],h[maxn],size[maxn],ff[maxn],vis[maxn];struct edge{int v,next;}e[maxn*2];void adde(int a,int b){e[tot].v=b,e[tot].next=head[a];head[a]=tot++;}int find(int x){return ff[x]==x ? x : ff[x]=find(ff[x]);}bool unio(int x,int y){int dx=find(x),dy=find(y);if(dx==dy)return false;ff[dx]=dy,size[dy]+=size[dx];return true;}void insert(int x,int& y,int l,int r,int id){y=++num;ls[y]=ls[x],rs[y]=rs[x],s[y]=s[x]+1;if(l==r)return ;int mid=l+r>>1;if(id>mid)insert(rs[x],rs[y],mid+1,r,id);else insert(ls[x],ls[y],l,mid,id);}int query(int x,int y,int z,int fz,int l,int r,int k){if(l==r)return t[l];int mid=l+r>>1,sum=s[ls[x]]+s[ls[y]]-s[ls[z]]-s[ls[fz]];if(sum>=k)return query(ls[x],ls[y],ls[z],ls[fz],l,mid,k);else return query(rs[x],rs[y],rs[z],rs[fz],mid+1,r,k-sum);}void dfs(int u,int fa){f[u][0]=fa,h[u]=h[fa]+1,vis[u]=1;insert(rt[fa],rt[u],1,nn,val[u]);for(int i=1;i<=17;i++)f[u][i]=f[f[u][i-1]][i-1];for(int v,i=head[u];i;i=e[i].next){if((v=e[i].v)==fa)continue;dfs(v,u);;}}int lca(int a,int b){if(h[a]>h[b])swap(a,b);for(int i=17;i>=0;i--)if(h[f[b][i]]>=h[a])b=f[b][i];if(a==b)return a;for(int i=17;i>=0;i--){if(f[a][i]==f[b][i])continue;a=f[a][i],b=f[b][i];}return f[a][0];}void link(int a,int b){int dx=find(a),dy=find(b);if(size[dx]>size[dy])swap(a,b),swap(dx,dy);//a所在的树更小 unio(a,b);adde(a,b),adde(b,a);dfs(a,b);}int main(){scanf("%d",&T);n=read(),m=read(),cl=read();for(int i=1;i<=n;i++)ff[i]=i,size[i]=1;for(int i=1;i<=n;i++)val[i]=t[i]=read();sort(t+1,t+1+n);nn=unique(t+1,t+1+n)-t-1;for(int i=1;i<=n;i++)val[i]=lower_bound(t+1,t+1+nn,val[i])-t;int a=0,b=0,c=0,g;for(int i=1;i<=m;i++){a=read(),b=read();adde(a,b),adde(b,a);unio(a,b);}for(int i=1;i<=n;i++)if(!vis[i])dfs(find(i),0);char s[5];int ans=0;while(cl--){scanf("%s",s);if(s[0]=='Q'){a=read(),b=read(),c=read();a^=ans,b^=ans,c^=ans;g=lca(a,b);printf("%d\n",ans=query(rt[a],rt[b],rt[g],rt[f[g][0]],1,nn,c));}else {a=read(),b=read();a^=ans,b^=ans;link(a,b);}}return 0;}