bzoj3223Tyvj 1729 文艺平衡树

bzoj3223Tyvj 1729 文艺平衡树

题意：

一个数列，支持区间翻转操作。

题解：

splay裸题。注意涉及到区间操作的一般用splay不用treap。

代码：

 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 #define inc(i,j,k) for(int i=j;i<=k;i++)
 #define fa(x) nds[x].fa
 #define ch(x,y) nds[x].ch[y]
 #define tg(x) nds[x].tg
 #define v(x) nds[x].v
 #define sz(x) nds[x].sz
 using namespace std;

 struct nd{int fa,ch[],v,sz,tg;};
 nd nds[]; int size,root,n,m; bool first;
 void pushdown(int x){
     if(! x)return; if(tg(x)){
         if(ch(x,)&&ch(x,))swap(ch(x,),ch(x,)),tg(ch(x,))^=,tg(ch(x,))^=;else
         if(ch(x,))ch(x,)=ch(x,),ch(x,)=,tg(ch(x,))^=;else ch(x,)=ch(x,),ch(x,)=,tg(ch(x,))^=;
         tg(x)^=;
     }
 }
 void update(int x){if(! x)return; sz(x)=sz(ch(x,))+sz(ch(x,))+;}
 void rotate(int x){
     if(x==||fa(x)==)return;
     int a1=fa(x),a2=fa(a1); bool a3=(x==ch(a1,)),a4=(a1==ch(a2,));
     if(a2)ch(a2,a4)=x; if(ch(x,!a3))fa(ch(x,!a3))=a1; ch(a1,a3)=ch(x,!a3); ch(x,!a3)=a1;
     fa(x)=a2; fa(a1)=x; update(a1); update(x); if(a2)update(a2);
 }
 void splay(int x,int y){
     if(x==||y==)return; int z=fa(y); if(y==root)root=x;
     while(fa(x)!=z){
         if(fa(fa(x))!=z){
             if((x==ch(fa(x),))^(fa(x)==ch(fa(fa(x)),)))rotate(x);else rotate(fa(x));
         }
         rotate(x);
     }
 }
 int build(int l,int r){
     if(l>r)return ;
     ++size; int ff=size; int m=(l+r)>>; ch(ff,)=build(l,m-); ch(ff,)=build(m+,r);
     if(ch(ff,))fa(ch(ff,))=ff; if(ch(ff,))fa(ch(ff,))=ff;
     v(ff)=m; tg(ff)=; update(ff); return ff;
 }
 int find(int p){
     int x=root; while(){
         if(x==)return ; pushdown(x);
         int a1=sz(ch(x,)); if(a1+==p)return x;
         if(a1+<p)p-=(a1+),x=ch(x,);else x=ch(x,);
     }
 }
 void rever(int l,int r){
     int a1=find(l-),a2=find(r+); splay(a2,root);
     if(l>)splay(a1,ch(a2,)),tg(ch(a1,))^=;else tg(ch(a2,))=;
 }
 void print(int x){
     if(x==)return; pushdown(x);
     print(ch(x,));
     if(v(x)!=n+)
         if(!first)printf("%d",v(x)),first=;else printf(" %d",v(x));
     print(ch(x,));
 }
 int main(){
     //freopen("test.txt","r",stdin);
     scanf("%d%d",&n,&m); size=; root=build(,n+);
     inc(i,,m){
         int a,b; scanf("%d%d",&a,&b); rever(a,b);
     }
     first=; print(root);
     return ;
 }

20160418