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-9;

inline int sgn(DB x){if(abs(x)<EPS)return 0;return(x>0)?1:-1;}

const DB Pi=acos(-1.0);



inline int gint()

  {

        int res=0;bool neg=0;char z;

        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());

        if(z==EOF)return 0;

        if(z=='-'){neg=1;z=getchar();}

        for(;z!=EOF && isdigit(z);res=res*10+z-'0',z=getchar());

        return (neg)?-res:res; 

    }

inline LL gll()

  {

      LL res=0;bool neg=0;char z;

        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());

        if(z==EOF)return 0;

        if(z=='-'){neg=1;z=getchar();}

        for(;z!=EOF && isdigit(z);res=res*10+z-'0',z=getchar());

        return (neg)?-res:res; 

    }



const int maxN=200000;

const int maxcnt=2*maxN;

const int INF=2147483647;



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=0,int _r=0,int _id=0){l=_l;r=_r;id=_id;}

    }a[maxN+100],temp[maxN+100];



int flag[maxN+100];

int ans;

PII fin[maxN+100];int tol;



int cnt,bak[maxcnt+100];



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



int tree[maxcnt+100];



int next[maxN+100];

int jump[maxN+100][31];



#define lowbit(a) (a&(-a))

inline int ask(int p)

  {

      p=cnt-p+1;

      int res=INF;

      for(;p>=1;p-=lowbit(p))upmin(res,tree[p]);

      return res;

  }

inline void update(int p,int v)

  {

      p=cnt-p+1;

      for(;p<=cnt;p+=lowbit(p))upmin(tree[p],v);

  }



PII tr[4*maxcnt+1000];

inline void down(int root,int l,int r,int mid)

  {

      if(tr[root]!=PII(0,0))

        {

            tr[root*2]=tr[root*2+1]=tr[root];

            tr[root]=PII(0,0);

        }

  }

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)/2;

      down(root,l,r,mid);

      if(p<=mid) askf(root*2,l,mid,p,x,y); else askf(root*2+1,mid+1,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)/2;

      down(root,l,r,mid);

      updatef(root*2,l,mid,x,y,val);

      updatef(root*2+1,mid+1,r,x,y,val);

  }



inline int solve(int x,int y)

  {

      if(x>y)return 0;

      int res=0,i,p=lower_bound(a+1,a+N+1,Ta(x,0,0))-a;

      if(p>N)return 0;

      red(i,30,0)

          if(jump[p][i]!=0 && 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-1);

      int t3=solve(r+1,y);

      return solve(x,y)==solve(x,l-1)+1+solve(r+1,y);

  }



int main()

  {

      freopen("bzoj1178.in","r",stdin);

      freopen("bzoj1178.out","w",stdout);

        int i,j;

        N=gint();

        re(i,1,N)a[i].l=gint(),a[i].r=gint(),a[i].id=i;

        re(i,1,N)bak[++cnt]=a[i].l,bak[++cnt]=a[i].r;

        sort(bak+1,bak+cnt+1);

        cnt=unique(bak+1,bak+cnt+1)-bak-1;

        re(i,1,N)a[i].l=lower_bound(bak+1,bak+cnt+1,a[i].l)-bak,a[i].r=lower_bound(bak+1,bak+cnt+1,a[i].r)-bak;

        re(i,1,N)fin[a[i].id]=PII(a[i].l,a[i].r);

        tol=N;

        sort(a+1,a+N+1,cmpr);

        int t=0;

        re(i,1,N){if(a[i].l<=t)flag[i]=1;upmax(t,a[i].l);}

        int ge=0;

        re(i,1,N)if(!flag[i])temp[++ge]=a[i];

        N=ge;

        re(i,1,N)a[i]=temp[i];

        t=0;

        re(i,1,N)if(t<a[i].l){ans++;t=a[i].r;}

        cout<<ans<<endl;

        re(i,1,cnt)tree[i]=INF;

        red(i,N,1)

          {

              next[i]=ask(a[i].r+1);if(next[i]==INF) next[i]=0;

              update(a[i].l,i);

          }

        red(i,N,1)

          {

              jump[i][0]=next[i];

              re(j,1,30)jump[i][j]=jump[jump[i][j-1]][j-1];

          }

        re(i,1,4*maxcnt+1000-1)tr[i]=PII(1,cnt);

        re(i,1,tol)

          {

              int l=fin[i].fi,r=fin[i].se,x,y;

              askf(1,1,cnt,l,x,y);

              if(x==-1 && y==-1)continue;

              if(!(x<=l && r<=y))continue;

              if(check(x,y,l,r))

                {

                    printf("%d ",i);

                    ans--;if(ans==0)break;

                    updatef(1,1,cnt,l,r,PII(-1,-1));

                    updatef(1,1,cnt,x,l-1,PII(x,l-1));

                    updatef(1,1,cnt,r+1,y,PII(r+1,y));

                }

          }

        printf("\n");

        return 0;

  }

View Code