# 【BZOJ】3223: Tyvj 1729 文艺平衡树（splay）

http://www.lydsy.com/JudgeOnline/problem.php?id=3223

#include <cstdio>
#include <cstring>
#include <cmath>
#include <string>
#include <iostream>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i=0; i<(n); ++i)
#define for1(i,a,n) for(int i=(a);i<=(n);++i)
#define for2(i,a,n) for(int i=(a);i<(n);++i)
#define for3(i,a,n) for(int i=(a);i>=(n);--i)
#define for4(i,a,n) for(int i=(a);i>(n);--i)
#define CC(i,a) memset(i,a,sizeof(i))
#define print(a) printf("%d", a)
#define dbg(x) cout << (#x) << " = " << (x) << endl
#define error(x) (!(x)?puts("error"):0)
#define rdm(x, i) for(int i=ihead[x]; i; i=e[i].next)
inline const int getint() { int r=0, k=1; char c=getchar(); for(; c<'0'||c>'9'; c=getchar()) if(c=='-') k=-1; for(; c>='0'&&c<='9'; c=getchar()) r=r*10+c-'0'; return k*r; }

struct node *null;
struct node {
node *f, *c[2];
int s, k;
bool rev;
node(int _k=0) { f=c[0]=c[1]=null; k=_k; s=1; rev=0; }
bool d() { return f->c[1]==this; }
void setc(node *x, bool d) { c[d]=x; x->f=this; }
void pushup() { s=1+c[0]->s+c[1]->s; }
void upd() { if(this==null) return; rev=!rev; swap(c[0], c[1]); }
void pushdown() { if(rev) rev=0, c[0]->upd(), c[1]->upd(); }
}*root;
void rot(node *x) {
node *f=x->f;
f->pushdown(); x->pushdown(); bool d=x->d();
f->f->setc(x, f->d());
f->setc(x->c[!d], d);
x->setc(f, !d);
f->pushup();
if(f==root) root=x;
}
void splay(node *x, node *f=null) {
x->pushdown();
while(x->f!=f)
if(x->f->f==f) rot(x);
else x->d()==x->f->d()?(rot(x->f), rot(x)):(rot(x), rot(x));
x->pushup();
}
node *sel(node *x, int k) {
if(x==null) return null;
x->pushdown();
int s=x->c[0]->s;
if(s==k) return x;
if(s<k) return sel(x->c[1], k-s-1); return sel(x->c[0], k);
}
node *getrange(int l, int r) {
splay(sel(root, l-1));
splay(sel(root, r+1), root);
return root->c[1]->c[0];
}
void build(int l, int r, node *&x) {
if(l>r) return;
int mid=(l+r)>>1;
x=new node(mid);
if(l==r) return;
build(l, mid-1, x->c[0]);
build(mid+1, r, x->c[1]);
if(l<=mid-1) x->c[0]->f=x;
if(mid+1<=r) x->c[1]->f=x;
x->pushup();
}
int n, m;
void init() {
null=new node; null->s=0;
null->f=null->c[0]=null->c[1]=null;
root=new node;
root->setc(new node, 1);
node *x;
build(1, n, x);
root->c[1]->setc(x, 0);
root->c[1]->pushup();
root->pushup();
}
void rev() {
int l=getint(), r=getint();
node *x=getrange(l, r);
x->upd();
}
void Pr(node *x) { if(x==null) return; x->pushdown(); Pr(x->c[0]); printf("%d ", x->k); Pr(x->c[1]); }
void P() {
node *x=getrange(1, n);
Pr(x);
}
int main() {
init();
while(m--) rev();
P();
return 0;
}


5 3

1 3

1 3

1 4

4 3 2 1 5

N,M<=100000

## Source

posted @ 2014-12-09 00:02  iwtwiioi  阅读(373)  评论(0编辑  收藏  举报