Submission #1255834

#	Time	Username	Problem	Language	Result	Execution time	Memory
1255834		erering	Rarest Insects (IOI22_insects)	C++20	74.15 / 100	34 ms	524 KiB

insects

#include <bits/stdc++.h>
#include "insects.h"
using namespace std;
int min_cardinality(int N) {
    int cnt=0;
    set<int> in;
    vector<int> ids;
    for(int i=0;i<N;i++){
        ids.push_back(i);
        move_inside(i);
        int x=press_button();
        if(x>1)move_outside(i);
        else{
            cnt++;
            in.insert(i);
        }
    }
    if(cnt==1)return N;
    int l=1,r=N/cnt;
    std::random_device rd;
    std::mt19937 g(rd());
    std::shuffle(ids.begin(), ids.end(), g);
    while(l<r){
        int mid=(l+r+1)/2;
        if(r-l>=4)mid=l+(r-l)/4;
        vector<int> nw;
        for(int id=0;id<N;id++){
            int i=ids[id];
            if(in.size()==mid*cnt || in.find(i)!=in.end())continue;
            move_inside(i);
            int x=press_button();
            if(x>mid)move_outside(i);
            else{
                in.insert(i);
                nw.push_back(i);
            }
        }
        if(in.size()==mid*cnt){
            l=mid;
        }
        else{
            r=mid-1;
            for(auto i:nw){
                move_outside(i);
                in.erase(i);
            }
        }
    }
    return l;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 49.15 / 75