[BST-SBT]POJ_3481_double queue

#include<iostream>
#include<cstdio>
using namespace std;
const int MAXN = 1111111,INF = 10000001;
struct Key{
int k,p;
Key(){}
Key(int kk,int pp):k(kk),p(pp){}
bool operator < (const Key &ke) const{
return p<ke.p;
}
bool operator >= (const Key &ke) const{
return !(*this<ke);
}
bool operator == (const Key &ke) const{
return p==ke.p;
}
}k[MAXN];
int l[MAXN],r[MAXN],pool[MAXN],size[MAXN],T,top,node;
void build(){
T = top = node = 0;
}
void left_rotate(int &x){
int q = r[x];
r[x] = l[q];
l[q] = x;
size[q] = size[x];
size[x] = size[l[x]]+size[r[x]]+1;
x = q;
}
void right_rotate(int &x){
int q = l[x];
l[x] = r[q];
r[q] = x;
size[q] = size[x];
size[x] = size[l[x]]+size[r[x]]+1;
x = q;
}
int newnode(Key key){
int x;
if(top!=0){
x = pool[--top];
}else{
x = ++node;
}
k[x] = key;
size[x] = 1; l[x] = r[x] = 0;
return x;
}
void delnode(int x){
pool[top++] = x;
size[x] = l[x] = r[x] = 0;
}
void Maintain(int &T,bool flag){
if(!flag){
if(size[l[l[T]]]>size[r[T]]){
right_rotate(T);
}else if(size[r[l[T]]]>size[r[T]]){
left_rotate(l[T]);
right_rotate(T);
}else{
return;
}
}else{
if(size[r[r[T]]]>size[l[T]]){
left_rotate(T);
}else if(size[l[r[T]]]>size[l[T]]){
right_rotate(r[T]);
left_rotate(T);
}else{
return;
}
}
Maintain(l[T],0);
Maintain(r[T],1);
Maintain(T,0);
Maintain(T,1);
}
void Insert(int &T,Key key){
if(!T){
T = newnode(key);
return;
}
size[T]++;
if(key<k[T])Insert(l[T],key);
else Insert(r[T],key);
Maintain(T,key>=k[T]);
}
Key Delete(int &T,Key key){
if(!T)return Key(INF,INF);//no element to delete
size[T]--;
if((key==k[T])||(key<k[T]&&l[T]==0)||(key>=k[T]&&r[T]==0)){
Key ret = k[T]; int x = T;
if(l[T]==0||r[T]==0){
T = l[T]+r[T];
delnode(x);//释放结点内存
}else{
key.p++;
k[T] = Delete(r[T],key);
}
return ret;
}
if(key<k[T])Delete(l[T],key);
else Delete(r[T],key);
}
Key DeleteMax(int &T){
if(!T)return Key(INF,INF);
if(r[T])return DeleteMax(r[T]);
int x = T; Key key = k[T];
T = l[T];
delnode(x);
return key;
}
Key DeleteMin(int &T){
if(!T)return Key(INF,INF);
if(l[T])return DeleteMin(l[T]);
int x = T; Key key = k[T];
T = r[T];
delnode(x);
return key;
}
Key Select(int T,int st){
if(!T)return Key(INF,INF);
int rank = size[l[T]]+1;
if(st==rank)return k[T];
else if(st<rank)return Select(l[T],st);
else return Select(r[T],st-rank);
}
int Rank(int T,Key key){
if(!T)return -1;
if(key==k[T])return size[l[T]]+1;
else if(key<K[T])return Rank(l[T],key);
else return size[l[T]]+1+Rank(r[T],key);
}
int main(){
int op,rst,sec;
build();
//freopen("out.txt","w",stdout);
while(scanf("%d",&op),op){
if(op==1){
scanf("%d%d",&rst,&sec);
Insert(T,Key(rst,sec));
}else if(op==2){
Key key = Select(T,size[T]);
if(key.k==INF)printf("0\n");
else printf("%d\n",key.k);
Delete(T,key);
}else{
Key key = Select(T,1);
if(key.k==INF)printf("0\n");
else printf("%d\n",key.k);
Delete(T,key);
}
}
return 0;
}