Boring Class cdq分治

#include<bits/stdc++.h>
using namespace std;
//input by bxd
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define repp(i,a,b) for(int i=(a);i>=(b);--i)
#define RI(n) scanf("%d",&(n))
#define RII(n,m) scanf("%d%d",&n,&m)
#define RIII(n,m,k) scanf("%d%d%d",&n,&m,&k)
#define RS(s) scanf("%s",s);
#define ll long long
#define see(x) (cerr<<(#x)<<‘=‘<<(x)<<endl)
#define pb push_back
#define inf 0x3f3f3f3f
#define CLR(A,v)  memset(A,v,sizeof A)
#define lson l,m,pos<<1
#define rson m+1,r,pos<<1|1
typedef pair<int,int>pii;
//////////////////////////////////
const int N=1e6+10;
int M,t[N],n,cnt,num,ans[N],maxx,m;
int lowbit(int i){return i&(-i);}
void add(int x,int v){for(;x<=m+1;x+=lowbit(x))t[x]=max(t[x],v);}
int qsum(int x){int ans=0;for(;x;x-=lowbit(x)) ans=max(ans,t[x]);return ans;}
void upclear(int x){for(;x<=N;x+=lowbit(x))t[x]=0;}
int dp[N];
struct node
{
    int l,r,id;
    bool operator < (const node & b)
    {
        if(r!=b.r)return r<b.r;
        if(l!=b.l)return l>b.l;
        return id<b.id;
    }
}s[N],p1[N],p2[N];

void cdq(int l,int r)
{
    int mid=(l+r)>>1;
    if(l==r){dp[s[l].id]=max(dp[s[l].id],1);return ;}
    cdq(mid+1,r);

    rep(i,l,mid)p1[i]=s[i];rep(i,mid+1,r)p2[i]=s[i];
    sort(p1+l,p1+mid+1);sort(p2+mid+1,p2+r+1);

    for(int i=mid,j=r;i>=l ;i--)
    {
        while(j>mid&&p2[j].r>=p1[i].r)add(p2[j].l,dp[p2[j].id]),j--;
        dp[p1[i].id]=max(dp[p1[i].id],qsum(p1[i].l)+1);
    }
    for(int i=mid+1;i<=r;i++)upclear(p2[i].l);

    cdq(l,mid);
}
int table[N];

int sol()
{
    CLR(dp,0);CLR(t,0);
    cnt=0;
    rep(i,1,n)RI(s[i].l),table[++cnt]=s[i].l;
    rep(i,1,n)RI(s[i].r),s[i].id=i,table[++cnt]=s[i].r;
    sort(table+1,table+1+cnt);
    m=unique(table+1,table+1+cnt)-table-1;
    rep(i,1,n)
    {
        s[i].l=lower_bound(table+1,table+1+m,s[i].l)-table;
        s[i].r=lower_bound(table+1,table+1+m,s[i].r)-table;
    }
    cdq(1,n);
    
    int maxx=0;
    rep(i,1,n)maxx=max(maxx,dp[i]);
    cout<<maxx<<endl;
    int ok=1,pre=0;
    rep(i,1,n)
    {
        if(dp[i]==maxx&&(pre==0||s[pre].l>=s[i].l&&s[pre].r<=s[i].r ))
        {
            if(ok)ok=0;else printf(" ");
            printf("%d",i);
            maxx--;pre=i;
        }
    }
    cout<<endl;
}
int main()
{
    while(~RI(n))sol();
}