sgu187&&spoj7734

题解：

splay翻转（只有翻转

sgu ac，spoj tle

代码：

#pragma GCC optimize(2)
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N=;
int n,m,sz,rt,pre[N],cas,l,r,c[N][],alen,data[N],size[N],rev[N];
void pushup(int k)
{
    size[k]=size[c[k][]]+size[c[k][]]+;
}
void pushdown(int k)
{
    int l=c[k][],r=c[k][];
    if(rev[k])
     {
        swap(c[k][],c[k][]);
        rev[l]^=;rev[r]^=;
        rev[k]=;
     }
}
void rotate(int x,int &k)
{
    int y=pre[x],z=pre[y],l,r;
    if(c[y][]==x)l=;
    else l=;
    r=l^;
    if(y==k)k=x;
    else {if(c[z][]==y)c[z][]=x;else c[z][]=x;}
    pre[x]=z;pre[y]=x;pre[c[x][r]]=y;
    c[y][l]=c[x][r];c[x][r]=y;
    pushup(y);pushup(x);
}
void splay(int x,int &k)
{
    while(x!=k)
     {
        int y=pre[x],z=pre[y];
        if(y!=k)
          {
            if(c[y][]==x^c[z][]==y)rotate(x,k);
            else rotate(y,k);
         }
        rotate(x,k);
     }
}
int find(int k,int rank)
{
    pushdown(k);
    int l=c[k][],r=c[k][];
    if (size[l]+==rank)return k;
    else if (size[l]>=rank)return find(l,rank);
    else return find(r,rank-size[l]-);
}
void change(int l,int r)
{
    int x=find(rt,l),y=find(rt,r+);
    splay(x,rt);splay(y,c[x][]);
    int z=c[y][];
    rev[z]^=;
}
void build(int l,int r,int f)
{
    if(l>r)return;
    int now=data[l],last=data[f];
    if(l==r)
     {
        pre[now]=last;size[now]=;
        if(l<f)c[last][]=now;
        else c[last][]=now;
        return;
     }
    int mid=(l+r)>>;now=data[mid];
    build(l,mid-,mid);
    build(mid+,r,mid);
    pre[now]=last;pushup(mid);
    if(mid<f)c[last][]=now;
    else c[last][]=now;
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=;i<=n+;i++)data[i]=++sz;
    build(,n+,);rt=(n+)>>;
    while (m--)
     {
        scanf("%d%d",&l,&r);
        if (l!=r)change(l,r);
     }
    for(int i=;i<=n+;i++)printf("%d\n",find(rt,i)-);
}