因为需要用到区间修改，所以该用splay（尚未填坑）或者无旋treap（刚刚填上）

最开始的建树用到了建笛卡尔树的方法，把id大于当前点的点不断出栈，又因为这道题的点是按序入栈的，所以当它无法让更多点出栈时，他就是栈首的右子树，而最后一个出栈的点，就是当前点的左子树。显然root=zhan[1]。

#include<stdio.h>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cmath>
#define inf 10000000
using namespace std;
int n,m;
struct treap
{treap* ch[2];int id,h,lazy,size;treap(){size=lazy=h=0;id=rand();ch[1]=ch[0]=NULL;}inline void update(){size=ch[0]->size+ch[1]->size+1;}
} *null=new treap(),*root=null,*zhan[100005],*x,*last;
typedef pair<treap*,treap*> D;
inline int read()
{int sum=0,f=1;char x=getchar();while(x<'0'||x>'9'){if(x=='-')f=-1;x=getchar();}while(x>='0'&&x<='9'){sum=sum*10+x-'0';x=getchar();}return sum*f;
}
inline treap* newtreap(int x)
{treap *o=new treap();o->size=1;o->h=x;o->ch[0]=o->ch[1]=null;return o;
}
void push(treap *f)
{if(f==null)return;if(f->lazy){f->lazy^=1;if(f->ch[0]!=null)f->ch[0]->lazy^=1;if(f->ch[1]!=null)f->ch[1]->lazy^=1;swap(f->ch[0],f->ch[1]);}
}
D split(treap *f,int k)
{if(f==null)return  D(null,null);push(f);D y;if(f->ch[0]->size>=k){y=split(f->ch[0],k);f->ch[0]=y.second;f->update();y.second=f;}else{y=split(f->ch[1],k-f->ch[0]->size-1);f->ch[1]=y.first;f->update();y.first=f;}    return y;
}
treap* merge(treap *a,treap *b)
{if(a==null)return b;if(b==null)return a;push(a);push(b);if(a->id<b->id){a->ch[1]=merge(a->ch[1],b);a->update();return a;}else{b->ch[0]=merge(a,b->ch[0]);b->update();return b;}
}
void dfs(treap *x)
{if(x==null)return;push(x);if(x->ch[0]!=null)dfs(x->ch[0]);printf("%d ",x->h);if(x->ch[1]!=null)dfs(x->ch[1]);
}
int yjn()
{freopen("sph.in","r",stdin);freopen("sph.out","w",stdout);scanf("%d%d",&n,&m);int p=0;for(int i=1;i<=n;i++){x=newtreap(i);last=null;while(p&&zhan[p]->id>x->id){zhan[p]->update();last=zhan[p];zhan[p--]=null;}if(p)zhan[p]->ch[1]=x;x->ch[0]=last;zhan[++p]=x;}while(p)zhan[p--]->update();root=zhan[1];int l,r;for(int i=1;i<=m;i++){l=read();r=read();D x=split(root,r);D y=split(x.first,l-1);if(y.second!=null)y.second->lazy^=1;root=merge(merge(y.first,y.second),x.second);}dfs(root);
}
int qty=yjn();
int main(){;}