Submission #831330

#	Time	Username	Problem	Language	Result	Execution time	Memory
831330		definitelynotmee	Rarest Insects (IOI22_insects)	C++17	100 / 100	55 ms	484 KiB

insects

// Fifth submission after reading edi
#include "insects.h"
#include<bits/stdc++.h>
#define all(x) x.begin(), x.end()
using ll = long long;
using namespace std;
template<typename T>
using matrix = vector<vector<T>>;


struct Machine {
    set<int> s;

    void insert(int id){
        s.insert(id);
        move_inside(id);
    }
    void erase(int id){
        s.erase(id);
        move_outside(id);
    }

    int resp(){
        return press_button();
    }
    void clear(){
        auto it  = s.begin();
        while(it!=s.end()){
            move_outside(*it);
            it = s.erase(it);
        }
    }
};

int min_cardinality(int N) {
    mt19937 rng(time(nullptr));
    vector<int> dif;
    vector<int> v;

    Machine m;

    for(int i = 0; i < N; i++){
        m.insert(i);
        if(m.resp() == 1){
            dif.push_back(i);
        } else m.erase(i);
        v.push_back(i);
    }

    shuffle(all(v),rng);


    m.clear();

    int ini = 1, fim = N/dif.size();

    vector<int> curinsert, lastinsert;

    auto putless =[&](int mx){
        for(int i : v){
            if(m.s.count(i))
                continue;
            m.insert(i);
            if(m.resp() > mx)
                m.erase(i);
            else curinsert.push_back(i);

            if(m.s.size() == dif.size()*mx)
                break;
        }
    };

    int last = -1;

    while(ini!=fim){
        int mid = (ini+fim+1)>>1;

        // cerr << "mid = " << mid << '\n';
        
        if(mid < last){
            vector<int> newv;

            for(int i : m.s)
                newv.push_back(i);
            swap(v,newv);
            for(int i : lastinsert)
                m.erase(i);
        }
        
        putless(mid);

        bool ok = m.s.size()%mid == 0 && m.s.size()/mid == dif.size();
        if(ok)
            ini = mid;
        else fim = mid-1;
        last = mid;

        swap(curinsert,lastinsert);
        curinsert.clear();
    } 
    return ini;

    

}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 75 / 75