bzoj2733

1.treap

每个点建一棵treap，维护优先级,然后启发式合并两棵treap

#include<cstdio>
#include<cctype>
#include<algorithm>
#define maxn 100002
using namespace std;
int rt[maxn],fa[maxn],n,m,q;
struct data{int l,r,rnd,siz,key;data(){siz=1;l=r=rnd=0;}}tr[maxn];
int findfa(int x){if(fa[x]==x)return x;return fa[x]=findfa(fa[x]);}
void read(int &x){
    char ch=getchar();x=0;int f=1;
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
    x*=f;
}
void rturn(int &x){int tmp=tr[x].l;tr[x].l=tr[tmp].r;tr[tmp].r=x;tr[tmp].siz=tr[x].siz;tr[x].siz=tr[tr[x].l].siz+1+tr[tr[x].r].siz;x=tmp;}
void lturn(int &x){int tmp=tr[x].r;tr[x].r=tr[tmp].l;tr[tmp].l=x;tr[tmp].siz=tr[x].siz;tr[x].siz=tr[tr[x].l].siz+1+tr[tr[x].r].siz;x=tmp;}
void insert(int &rt,int x){
    if(!rt){rt=x;tr[x].rnd=rand();return;}
    tr[rt].siz++;
    if(tr[x].key<tr[rt].key){
        insert(tr[rt].l,x);
        if(tr[tr[rt].l].rnd<tr[rt].rnd)rturn(rt);
    }else{
        insert(tr[rt].r,x);
        if(tr[tr[rt].r],x);
        if(tr[tr[rt].r].rnd<tr[rt].rnd)lturn(rt);
    }
}
void merge_node(int x,int y){
    if(!y)return;
    merge_node(x,tr[y].l);
    merge_node(x,tr[y].r);
    insert(x,y);
}
void merge(int x,int y){
    int fx=findfa(x),fy=findfa(y);
    if(fx==fy)return;
    if(tr[fx].siz<tr[fy].siz)swap(fx,fy);
    fa[fy]=fx;
    merge_node(fx,fy);
}
int getkth(int x,int k){
    if(k<=tr[tr[x].l].siz)return getkth(tr[x].l,k);
    k-=tr[tr[x].l].siz+1;
    if(k==0)return x;
    return getkth(tr[x].r,k);
}
int main(){
    int a,b;tr[0].siz=0;
    read(n);read(m);
    for(int i=1;i<=n;i++)read(tr[i].key),fa[i]=i;
    for(int i=1;i<=m;i++){read(a);read(b);merge(a,b);}
    read(q);
    char cc;
    while(q--){
        scanf(" %c",&cc);read(a);read(b);
        if(cc=='Q'){a=findfa(a);if(tr[a].siz<b)printf("-1\n");else printf("%d\n",getkth(a,b));}else merge(a,b);
    }
}

 2.splay

#include<cstdio>
#include<cctype>
#include<algorithm>
#define maxn 100002
using namespace std;
int n,m,q,rt[maxn],f[maxn],father[maxn],key[maxn],pos[maxn],siz[maxn],tr[maxn][2];
void read(int &x){
    char ch=getchar();x=0;int f=1;
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
    x*=f;
}
int findfa(int x){
    if(f[x]==x)return x;return f[x]=findfa(f[x]);
}
inline void rotate(int x,int &rt){
    int fa=father[x],gfa=father[fa];int whicx=(tr[fa][1]==x);
    if(fa==rt)rt=x; else tr[gfa][(tr[gfa][1]==fa)]=x;
    father[x]=gfa; father[fa]=x;
    tr[fa][whicx]=tr[x][whicx^1]; father[tr[x][whicx^1]]=fa; tr[x][whicx^1]=fa;
    siz[fa]=siz[tr[fa][0]]+siz[tr[fa][1]]+1;
    siz[x]=siz[tr[x][0]]+siz[tr[x][1]]+1;
}
void splay(int x,int &rt){
    for(int y;y=father[x];rotate(x,rt))
       if(father[y])rotate((x==tr[y][0])==(y==tr[father[y]][0])?y:x,rt);
}
void insert(int x,int &rt,int ff){
    if(!rt){rt=x;father[x]=ff;return;}
    siz[rt]++;
    if(key[x]<key[rt])insert(x,tr[rt][0],rt);
    else insert(x,tr[rt][1],rt);
}
void merge_node(int x,int y){
    if(!x)return;
    if(tr[x][0])merge_node(tr[x][0],y);
    if(tr[x][1])merge_node(tr[x][1],y);
    insert(x,rt[y],0);
    splay(x,rt[y]);
}
void merge(int a,int b){
    int fta=findfa(a),ftb=findfa(b);
    if(fta==ftb)return;
    if(siz[rt[fta]]>siz[rt[ftb]])swap(fta,ftb);
    f[fta]=ftb;
    merge_node(rt[fta],ftb);
}
int query(int rt,int k){
    int u=rt;
    while(1){
        if(k<=siz[tr[u][0]])u=tr[u][0];
        else if(siz[tr[u][0]]+1==k)return key[u];
        else k-=siz[tr[u][0]]+1,u=tr[u][1];
    }
}
int main(){
    read(n);read(m);
    int a,b;
    for(int i=1;i<=n;i++){read(key[i]);pos[key[i]]=i;rt[i]=i;f[i]=i;siz[i]=1;}
    for(int i=1;i<=m;i++){read(a);read(b);merge(a,b);}
    int q;char ch;read(q);
    while(q--){
        scanf(" %c",&ch);read(a);read(b);
        if(ch=='Q'){if(siz[rt[findfa(a)]]<b)printf("-1\n");else printf("%d\n",pos[query(rt[findfa(a)],b)]);}
        else merge(a,b);
    }
}