bzoj1178

题目：http://www.lydsy.com/JudgeOnline/problem.php?id=1178

看ppt

http://wenku.baidu.com/link?url=dJv6LNme7syiLGM-TzbEEKXwx36JWEnI5HFrIlzfmzUXXg4HG8FDggj5WQS3EKL3k3p-sUYeJ268jCvN4t_kq2YPo3I4GXvaGulQjXrO3d7

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<stack>
#include<map>
#include<utility>
#include<set>
#include<bitset>
#include<vector>
#include<functional>
#include<deque>
#include<cctype>
#include<climits>
#include<complex>
//#include<bits/stdc++.h>适用于CF,UOJ，但不适用于poj

using namespace std;

typedef long long LL;
typedef double DB;
typedef pair<int,int> PII;
typedef complex<DB> CP;

#define mmst(a,v) memset(a,v,sizeof(a))
#define mmcy(a,b) memcpy(a,b,sizeof(a))
#define re(i,a,b)  for(i=a;i<=b;i++)
#define red(i,a,b) for(i=a;i>=b;i--)
#define fi first
#define se second
#define m_p(a,b) make_pair(a,b)
#define SF scanf
#define PF printf
#define two(k) (1<<(k))

template<class T>inline T sqr(T x){return x*x;}
template<class T>inline void upmin(T &t,T tmp){if(t>tmp)t=tmp;}
template<class T>inline void upmax(T &t,T tmp){if(t<tmp)t=tmp;}

const DB EPS=1e-;
inline int sgn(DB x){if(abs(x)<EPS)return ;return(x>)?:-;}
const DB Pi=acos(-1.0);

inline int gint()
  {
        int res=;bool neg=;char z;
        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());
        if(z==EOF)return ;
        if(z=='-'){neg=;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*+z-'',z=getchar());
        return (neg)?-res:res;
    }
inline LL gll()
  {
      LL res=;bool neg=;char z;
        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());
        if(z==EOF)return ;
        if(z=='-'){neg=;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*+z-'',z=getchar());
        return (neg)?-res:res;
    }

const int maxN=;
const int maxcnt=*maxN;
const int INF=;

int N;
struct Ta
  {
      int l,r,id;
      inline friend bool operator < (Ta x,Ta y){return x.l<y.l;}
      inline Ta(int _l=,int _r=,int _id=){l=_l;r=_r;id=_id;}
    }a[maxN+],temp[maxN+];

int flag[maxN+];
int ans;
PII fin[maxN+];int tol;

int cnt,bak[maxcnt+];

inline bool cmpr(Ta x,Ta y){return x.r<y.r;}

int tree[maxcnt+];

int next[maxN+];
int jump[maxN+][];

#define lowbit(a) (a&(-a))
inline int ask(int p)
  {
      p=cnt-p+;
      int res=INF;
      for(;p>=;p-=lowbit(p))upmin(res,tree[p]);
      return res;
  }
inline void update(int p,int v)
  {
      p=cnt-p+;
      for(;p<=cnt;p+=lowbit(p))upmin(tree[p],v);
  }

PII tr[*maxcnt+];
inline void down(int root,int l,int r,int mid)
  {
      if(tr[root]!=PII(,))
        {
            tr[root*]=tr[root*+]=tr[root];
            tr[root]=PII(,);
        }
  }
inline void askf(int root,int l,int r,int p,int &x,int &y)
  {
      if(l>r || p<l || r<p) return;
      if(p<=l && r<=p) {x=tr[root].fi;y=tr[root].se;return;}
      int mid=(l+r)/;
      down(root,l,r,mid);
      if(p<=mid) askf(root*,l,mid,p,x,y); else askf(root*+,mid+,r,p,x,y);
  }
inline void updatef(int root,int l,int r,int x,int y,PII val)
  {
      if(l>r || x>y || r<x || y<l)return;
      if(x<=l && r<=y){tr[root]=val;return;}
      int mid=(l+r)/;
      down(root,l,r,mid);
      updatef(root*,l,mid,x,y,val);
      updatef(root*+,mid+,r,x,y,val);
  }

inline int solve(int x,int y)
  {
      if(x>y)return ;
      int res=,i,p=lower_bound(a+,a+N+,Ta(x,,))-a;
      if(p>N)return ;
      red(i,,)
          if(jump[p][i]!= && a[jump[p][i]].r<=y)
            {
                res+=two(i);
                p=jump[p][i];
            }
        if(a[p].r<=y)res++;
        return res;
  }
inline int check(int x,int y,int l,int r)
  {
      int t1=solve(x,y);
      int t2=solve(x,l-);
      int t3=solve(r+,y);
      return solve(x,y)==solve(x,l-)++solve(r+,y);
  }

int main()
  {
      freopen("bzoj1178.in","r",stdin);
      freopen("bzoj1178.out","w",stdout);
        int i,j;
        N=gint();
        re(i,,N)a[i].l=gint(),a[i].r=gint(),a[i].id=i;
        re(i,,N)bak[++cnt]=a[i].l,bak[++cnt]=a[i].r;
        sort(bak+,bak+cnt+);
        cnt=unique(bak+,bak+cnt+)-bak-;
        re(i,,N)a[i].l=lower_bound(bak+,bak+cnt+,a[i].l)-bak,a[i].r=lower_bound(bak+,bak+cnt+,a[i].r)-bak;
        re(i,,N)fin[a[i].id]=PII(a[i].l,a[i].r);
        tol=N;
        sort(a+,a+N+,cmpr);
        int t=;
        re(i,,N){if(a[i].l<=t)flag[i]=;upmax(t,a[i].l);}
        int ge=;
        re(i,,N)if(!flag[i])temp[++ge]=a[i];
        N=ge;
        re(i,,N)a[i]=temp[i];
        t=;
        re(i,,N)if(t<a[i].l){ans++;t=a[i].r;}
        cout<<ans<<endl;
        re(i,,cnt)tree[i]=INF;
        red(i,N,)
          {
              next[i]=ask(a[i].r+);if(next[i]==INF) next[i]=;
              update(a[i].l,i);
          }
        red(i,N,)
          {
              jump[i][]=next[i];
              re(j,,)jump[i][j]=jump[jump[i][j-]][j-];
          }
        re(i,,*maxcnt+-)tr[i]=PII(,cnt);
        re(i,,tol)
          {
              int l=fin[i].fi,r=fin[i].se,x,y;
              askf(,,cnt,l,x,y);
              if(x==- && y==-)continue;
              if(!(x<=l && r<=y))continue;
              if(check(x,y,l,r))
                {
                    printf("%d ",i);
                    ans--;if(ans==)break;
                    updatef(,,cnt,l,r,PII(-,-));
                    updatef(,,cnt,x,l-,PII(x,l-));
                    updatef(,,cnt,r+,y,PII(r+,y));
                }
          }
        printf("\n");
        return ;
  }