Submission #629057

#	Time	Username	Problem	Language	Result	Execution time	Memory
629057		two_sides	Rarest Insects (IOI22_insects)	C++17	0 / 100	49 ms	440 KiB

insects

#include "insects.h"
#include <bits/stdc++.h>

namespace {
    using namespace std;

    mt19937 rng(chrono::high_resolution_clock
    ::now().time_since_epoch().count());

    set<int> inside, useless;
    vector<int> ord;

    void insert(int i) {
        inside.insert(i);
        move_inside(ord[i]);
    }

    void erase(int i) {
        inside.erase(i);
        move_outside(ord[i]);
    }

}

int min_cardinality(int n) {
    ord.resize(n);
    iota(ord.begin(), ord.end(), 0);
    shuffle(ord.begin(), ord.end(), rng);
    for (int i = 0; i < n; i++) {
        insert(i);
        if (press_button() > 1) erase(i);
    }
    int t = inside.size();
    int l = 1, r = n / t;
    while (l < r) {
        int m = (l + r + 1) / 2;
        vector<int> last;
        for (int i = 0; i < n; i++)
            if (!inside.count(i) && !useless.count(i)) {
                insert(i);
                if (press_button() > m) {
                    erase(i); useless.insert(i);
                } else {
                    last.push_back(i);
                    if (inside.size() == m * t) break;
                }
            }
        if (inside.size() == m * t) {
            for (int i : inside)
                useless.erase(i);
            l = m;
        } else {
            for (int i : last) erase(i);
            r = m - 1;
        }
    }
    return r;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:45:39: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   45 |                     if (inside.size() == m * t) break;
      |                         ~~~~~~~~~~~~~~^~~~~~~~
insects.cpp:48:27: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   48 |         if (inside.size() == m * t) {
      |             ~~~~~~~~~~~~~~^~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 75