代码重发一下
```cpp
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int n,m,cnt,l,r,root,a[N];
struct node{
int ch[2],fa,size,tag,val;
}spl[N];
#define ls(x) spl[x].ch[0]
#define rs(x) spl[x].ch[1]
inline int ident(int x,int f){return rs(x)==x;}
inline void update(int now)
{
spl[now].size=spl[ls(now)].size+spl[rs(now)].size+1;
return;
}
inline void pushdown(int x)
{
if(x&&spl[x].tag)
{
swap(ls(x),rs(x));
spl[ls(x)].tag^=1;
spl[rs(x)].tag^=1;
spl[x].tag=0;
}
return;
}
inline void connect(int x,int f,int s)
{
spl[f].ch[s]=x;
spl[x].fa=f;
return;
}
inline void rotate(int x)
{
int f=spl[x].fa,ff=spl[f].fa,k=ident(x,f);
connect(spl[x].ch[k^1],f,k);
connect(x,ff,ident(f,ff));
connect(f,x,k^1);
update(f),update(x);
return;
}
inline void splaying(int x,int top)
{
if(!top)root=x;
while(spl[x].fa!=top)
{
int f=spl[x].fa,ff=spl[f].fa;
if(ff!=top)ident(f,ff)^ident(x,f)?rotate(x):rotate(f);
rotate(x);
}
return;
}
inline int build(int l,int r,int fa=0)
{
if(l>r)return 0;
int mid=l+r>>1;
int now=++cnt;
spl[now]={{0,0},fa,1,0,a[mid]};
ls(now)=build(l,mid-1,now);
rs(now)=build(mid+1,r,now);
update(now);
return now;
}
inline int getnum(int rank)
{
int x=root,y=rank;
while(x)
{
pushdown(x);
if(y<=spl[ls(x)].size)x=ls(x);
else
{
y-=spl[ls(x)].size+1;
if(!y)break;
x=rs(x);
}
}
return x;
}
inline void ldr(int now)
{
pushdown(now);
if(ls(now))ldr(ls(now));
if(spl[now].val!=-0x3f3f3f3f&&spl[now].val!=0x3f3f3f3f)cout<<spl[now].val<<" ";
if(rs(now))ldr(rs(now));
return;
}
int main()
{
clock_t c1=clock();
#ifdef LOCAL
freopen("1.in","r",stdin);
freopen("1.out","w",stdout);
#endif
ios::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>m;
a[1]=-0x3f3f3f3f,a[n+2]=0x3f3f3f3f;
for(int i=1;i<=n;i++)
{
a[i+1]=i;
}
root=build(1,n+2);
while(m--)
{
cin>>l>>r;
int tx=getnum(l);
int ty=getnum(r+2);
splaying(tx,0);
splaying(ty,tx);
spl[ls(rs(root))].tag^=1;
}
ldr(root);
#ifdef LOCAL
cerr<<"Time used:"<<clock()-c1<<"ms";
#endif
return 0;
}
```
by AAA404 @ 2023-08-19 21:51:13
此贴终，死于ident函数
by AAA404 @ 2023-08-19 22:27:28