## 【Treap】[BZOJ 3224]Tyvj 1728 普通平衡树

#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <cctype>
#include <iostream>
using namespace std;
const int MAXN = 500000;
struct node{
int r, v, sz, number;
node *ch[2];
void rz(){sz = ch[0]->sz + ch[1]->sz + number;}
}Edges[MAXN+10], *ecnt = Edges, Tnull, *nil = &Tnull;
node *newnode(node *lch, node *rch, int v, int r){
++ecnt;
ecnt->ch[0] = lch;
ecnt->ch[1] = rch;
ecnt->v = v;
ecnt->r = r;
return ecnt;
}
node *retu;
int ret;
struct Treap{
node *root;
Treap(){root = nil; nil->ch[0] = nil->ch[1] = nil;}
void rotate(node *&n, bool d){
node *a = n->ch[d];
n->ch[d] = a->ch[!d]; n->rz();
a->ch[!d] = n; a->rz();
n = a;
}
void Insert(node *&rt, int val){
if(rt == nil){
rt = newnode(nil, nil, val, rand());
rt->number = 1;
rt->rz();
return ;
}
rt->sz++;
if(val == rt->v){
rt->number++;
}else if(val < rt->v){
Insert(rt->ch[0], val);
if(rt->ch[0]->r < rt->r)
rotate(rt, false);
}else if(val > rt->v){
Insert(rt->ch[1], val);
if(rt->ch[1]->r < rt->r)
rotate(rt, true);
}
}
void del(node *&rt, int val){
if(rt == nil) return ;
rt->sz--;
if(rt->v == val){
if(rt->number > 1){
rt->number--;
}
else if(rt->ch[0] == nil || rt->ch[1] == nil){
if(rt->ch[0]!=nil)
rt = rt->ch[0];
else
rt = rt->ch[1];
}
else{
if(rt->ch[0]->r > rt->ch[1]->r){
rotate(rt, false);
del(rt->ch[1], val);
rt->rz();
}else{
rotate(rt, true);
del(rt->ch[0], val);
rt->rz();
}
}
}else if(val < rt->v)
del(rt->ch[0], val);
else
del(rt->ch[1], val);
}
int Rank(node *rt, int val){
if(rt == nil) return ret+1;
if(rt->v == val)
return ret+rt->ch[0]->sz+1;
if(val < rt->v)
return Rank(rt->ch[0], val);
ret += rt->ch[0]->sz+rt->number;
return Rank(rt->ch[1], val);
}
void pre(node *rt, int val){
if(rt == nil) return ;
else if(rt->v <= val){
retu = rt;
pre(rt->ch[1], val);
}else
pre(rt->ch[0], val);
}
void bak(node *rt, int val){
if(rt == nil) return ;
else if(rt->v >= val){
retu = rt;
bak(rt->ch[0], val);
}else
bak(rt->ch[1], val);
}
int order(node *rt, int rk){
if(rt->sz < rk) return 0;
if(rk <= rt->ch[0]->sz)
return order(rt->ch[0], rk);
else if(rk > rt->ch[0]->sz+rt->number)
return order(rt->ch[1], rk-rt->ch[0]->sz-rt->number);
return rt->v;
}
}tp;
int main(){
//freopen("data10.in", "r", stdin);
int n;
scanf("%d", &n);
for(int i=0;i<n;i++){
int o, x;
scanf("%d %d", &o, &x);
switch(o){
case 1: tp.Insert(tp.root, x); break;
case 2: tp.del(tp.root, x); break;
case 3: ret = 0; printf("%d\n", tp.Rank(tp.root, x)); break;
case 4: printf("%d\n", tp.order(tp.root, x)); break;
case 5: retu = nil;tp.pre(tp.root, x-1); printf("%d\n", retu->v); break;
case 6: retu = nil;tp.bak(tp.root, x+1); printf("%d\n", retu->v); break;
}
}

return 0;
}

posted on 2015-06-07 11:36  JeremyGuo  阅读(114)  评论(0编辑  收藏  举报