Submission #895187

#	Time	Username	Problem	Language	Result	Execution time	Memory
895187		8pete8	Event Hopping 2 (JOI21_event2)	C++17	0 / 100	189 ms	60144 KiB

event2

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<float.h>
#include<limits.h>
#include <cassert>
#include<cmath>
#include<set>
#include<algorithm>
#include <iomanip>
#include<numeric> //gcd(a,b)
#include<bitset>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
using namespace std;
#define int long long
#define double long double
const int mod=998244353,mxn=2e5+5,lg=22,inf=1e18,minf=-1e18,Mxn=100000;
int n,k,sz;
struct info{int l,r,posl,posr,realid,id;};
bool cmp(info a,info b){return a.r<b.r;}
struct lazyseg{
	int v[4*mxn+10],add[4*mxn+10];
	void push(int pos,int l,int r){
		if(!add[pos])return;
		v[pos]=1;
		if(l!=r)add[pos*2]=add[pos],add[pos*2+1]=add[pos];
		add[pos]=0;
	}
	void update(int l,int r,int pos,int ql,int qr){
		push(pos,l,r);
		if(l>qr||r<ql)return;
		if(ql<=l&&r<=qr){
			add[pos]=1;
			push(pos,l,r);
			return;
		}
		int mid=l+(r-l)/2;
		update(l,mid,pos*2,ql,qr);
		update(mid+1,r,pos*2+1,ql,qr);
		v[pos]=v[pos*2]|v[pos*2+1];
	}
	int qry(int l,int r,int pos,int ql,int qr){
		if(ql>qr)return 0;
		push(pos,l,r);
		if(l>qr||r<ql)return 0;
		if(ql<=l&&r<=qr)return v[pos];
		int mid=l+(r-l)/2;
		return (qry(l,mid,pos*2,ql,qr)|qry(mid+1,r,pos*2+1,ql,qr));
	}
}t2,t3;
vector<info>v;
vector<int>compress;
int up[mxn+10][lg+5];
int32_t main(){
    fastio
    cin>>n>>k;
    for(int i=0;i<n;i++){
        int a,b;cin>>a>>b;
        v.pb({a,b,-1,-1,i,i});
        compress.pb(a);
        compress.pb(b);
    }
    sort(all(compress));
	unique(all(compress));
    sz=mxn;
    for(auto &i:v){
        i.posl=lb(all(compress),i.l)-compress.begin()+1;
        i.posr=lb(all(compress),i.r)-compress.begin()+1;
    }
	int cur=0;
	vector<info>v2(all(v));
	sort(all(v),cmp);
	for(int i=0;i<n;i++)v2[v[i].realid].id=i;
	int curcnt=0,at=0;
	for(int i=0;i<=lg;i++)for(int j=0;j<n;j++)up[j][i]=-1;
	for(int i=0;i<n;i++)while(cur<n&&v[cur].r<=v[i].l){
		up[cur][0]=i;
		cur++;
	}
	for(int j=1;j<=lg;j++)for(int i=0;i<n;i++)if(up[i][j-1]!=-1)up[i][j]=up[up[i][j-1]][j-1];
	for(int i=lg;i>=0;i--)if(up[at][i]!=-1)at=up[at][i],curcnt+=(1<<i);
  	vector<int>ans;
	set<int>st;
	for(int i=0;i<n;i++){
		if(t2.qry(0,sz,1,v2[i].posl,v2[i].posr-1)||t3.qry(0,sz,1,v2[i].posl+1,v2[i].posr))continue;//check intersect
		int upb=inf,l,r;
		auto it=st.lb(v2[i].id);
		if(it==st.begin())at=0;
		else{
			it--;
			at=(*it);
			it++;
		}
		l=at;
		int add=0;
		for(int j=lg;j>=0;j--)if(up[at][j]!=-1&&v[up[at][j]].posr<=v2[i].posl)at=up[at][j],add+=(1ll<<j);
		if(it!=st.end())r=(*it);
		else r=n-1;
		at=v2[i].id;
		for(int j=lg;j>=0;j--)if(up[at][j]!=-1&&v[up[at][j]].posr<=v[r].posl)at=up[at][j],add+=(1ll<<j);
		for(int j=lg;j>=0;j--)if(up[l][j]!=-1&&v[up[l][j]].posr<=v[r].posl)l=up[l][j],add-=(1ll<<j);
		if(curcnt+add+1<k)continue;
		curcnt+=add+1;
		t2.update(0,sz,1,v2[i].posl,v2[i].posr-1);
		t3.update(0,sz,1,v2[i].posl+1,v2[i].posr);
		ans.pb(i+1);
		st.insert(v2[i].id);
		if(ans.size()==k)break;
	}
	if(ans.size()<k)cout<<-1<<'\n';
	else for(int i=0;i<k;i++)cout<<ans[i]<<"\n";
	return 0;
}

Compilation message (stderr)

event2.cpp: In function 'int32_t main()':
event2.cpp:128:16: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  128 |   if(ans.size()==k)break;
      |      ~~~~~~~~~~^~~
event2.cpp:106:7: warning: unused variable 'upb' [-Wunused-variable]
  106 |   int upb=inf,l,r;
      |       ^~~
event2.cpp:130:15: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'long long int' [-Wsign-compare]
  130 |  if(ans.size()<k)cout<<-1<<'\n';
      |     ~~~~~~~~~~^~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 1
• Subtask 3: 0 / 31
• Subtask 4: 0 / 61