Submission #653407

#	Time	Username	Problem	Language	Result	Execution time	Memory
653407		Lobo	Rarest Insects (IOI22_insects)	C++17	100 / 100	65 ms	456 KiB

insects

#include "insects.h"
#include<bits/stdc++.h>
using namespace std;

const int maxn = 2020;
int n, in[maxn], qtd[maxn], block[maxn], blockout[maxn];
int ids[maxn];
int diff = 1;
int cnt = 0;
int cur = 1;

int check(int mid) {
    for(int i = 0; i < n; i++) {
        if(in[i] || block[i]) continue;
        move_inside(i); in[i] = 1; cnt++;
        int qry = press_button();
        if(qry > cur) {
            qtd[i] = qry;
        }
        cur = qry;
        if(cur > mid) {
            move_outside(i); in[i] = 0; cnt--;
            cur--;
        }
    }

    if(mid*diff == cnt) {
        return true;
    }
    return false;
}

int min_cardinality(int N) {
    n = N;
    int qtdN = n;
    
    // First count the number of different numbers
    move_inside(0); in[0] = 1; cnt++;
    qtd[0] = 1;
    for(int i = 1; i < n; i++) {
        move_inside(i); in[i] = 1; cnt++;
        qtd[i] = 1;
        diff++;
        int qry = press_button();
        blockout[i] = 1;
        if(qry == 2) {
            diff--;
            move_outside(i); in[i] = 0; cnt--;
            qtd[i] = 2;
            blockout[i] = 0;
        }
    }
    if(diff == 1) return n;
    if(diff == n) return 1;
    int l = 1;
    int r = min(n/2,(n+diff+1)/diff);
    int ans = 1;
    while(l <= r) {
        int mid = max(l,(l+r)/2); // I want to see if the answer is <= mid
        if(check(mid)) {
            ans = mid;
            l = mid+1;
            // Everyone that is in will not be take off anymore
            for(int i = 0; i < n; i++) {
                if(in[i]) blockout[i] = 1;
            }
        }
        else {
            r = mid-1;
            for(int i = 0; i < n; i++) {
                if(!in[i]) {
                    block[i] = 1;
                    qtdN--;
                }
                if(in[i] && !blockout[i]) {
                    move_outside(i); in[i] = 0; cnt--;
                }
            }
            cur = 0;
        }
        // r = min(r,qtdN/diff);
    }
    return ans;
}

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