Submission #595606

#	Time	Username	Problem	Language	Result	Execution time	Memory
595606		Deepesson	Event Hopping (BOI22_events)	C++17	25 / 100	762 ms	100852 KiB

events

#include <bits/stdc++.h>
#define MAX 10010
#define LSB(A) (A&(-A))
int N,Q;
typedef std::pair<int,int> pii;
std::vector<pii> eventos;

std::vector<int> add[MAX];

std::vector<int> rem[MAX];

int ft[MAX];

void upd(int a,int b){a+=3;
   // std::cout<<"Upd "<<a<<"\n";
    while(a<MAX){
        ft[a]=std::min(ft[a],b);
        a+=LSB(a);
    }
}

int query(int a){a+=3;
  //  std::cout<<"Upd "<<a<<"\n";
    int r=1e9;
    while(a>0){
        r=std::min(r,ft[a]);
        a-=LSB(a);
    }
    return r;
}

typedef std::pair<int,int*> pipo;
int custos[101000];
int trava;
void simula(int x){
    for(auto&x:ft)x=1e9;
    upd(MAX-eventos[x].second-5,1);
    for(int i=0;i!=N;++i)custos[i]=1e9;
    for(int i=eventos[x].second;i!=trava+1;++i){
        int minimo=1e9;
        for(auto&x:rem[i]){
            int d = query(MAX-eventos[x].first-5);
            custos[x]=d;
          //  std::cout<<x<<" "<<d<<" "<<MAX-eventos[x].first-5<<" "<<MAX-i-5<<"!\n";
            minimo=std::min(minimo,d+1);
        }
      //  std::cout<<minimo<<"\n";
        upd(MAX-i-5,minimo);
        for(auto&x:rem[i]){
            custos[x]=std::min(custos[x],minimo);
        }
    }
    custos[x]=0;
}
int tabp5[5005][5005];
int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    std::cout.tie(0);
    std::cin>>N>>Q;
    for(int i=0;i!=N;++i){
        int a,b;
        std::cin>>a>>b;
        eventos.push_back({a,b});
    }

    {
        std::vector<pipo> comprime;
        for(auto&x:eventos){
            comprime.push_back({x.first,&x.first});
            comprime.push_back({x.second,&x.second});
        }
        std::sort(comprime.begin(),comprime.end());
        int last=-1,cord=1;
        for(auto&x:comprime){
            if(x.first!=last){
                last=x.first;
                ++cord;
            }
            *x.second=cord;
        }
        trava=cord;
    }
    for(int i=0;i!=N;++i){
        rem[eventos[i].second].push_back(i);
    }
    if(N<=5005){
        for(int i=0;i!=N;++i){
            simula(i);
            for(int j=0;j!=N;++j)
                tabp5[i][j]=custos[j];
            ///!!!!
        }
        for(int i=0;i!=Q;++i){
            int a,b;
            std::cin>>a>>b;
            --a;--b;
            int d = tabp5[a][b];
            if(d>1e6){
                std::cout<<"impossible\n";
            }else {
                std::cout<<d<<"\n";
            }
        }
        return 0;
    }
    for(int i=0;i!=Q;++i){
        int a,b;
        std::cin>>a>>b;
        --a;--b;
        simula(a);
        int d = custos[b];
        if(d>1e6){
            std::cout<<"impossible\n";
        }else {
            std::cout<<d<<"\n";
        }
    }
}

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30