Submission #786340

#	Time	Username	Problem	Language	Result	Execution time	Memory
786340		vjudge1	Rarest Insects (IOI22_insects)	C++17	99.89 / 100	55 ms	328 KiB

insects

#include "insects.h"
#include <bits/stdc++.h>
using namespace std;
int min_cardinality(int N) {
    int cnt = 0;
    vector<bool> f(N);
    for (int i = 0; i < N; i++) {
        move_inside(i);
        if (press_button() <= 1) {
            f[i] = 1;
            cnt++;
        } else {
            move_outside(i);
        }
    }
    vector<int> blocked(N);
    for (int i = 0; i < N; i++) {
        if (f[i]) {
            blocked[i] = 1;
        }
    }
    int lo = 1, hi = N / cnt, in = cnt, ad = 1;
    while (lo < hi) {
        int mi = (lo + hi + 1) / 2;
        for (int i = 0; i < N; i++) {
            if (f[i] || blocked[i]) {
                continue;
            }
            move_inside(i);
            if (press_button() <= mi) {
                in++;
                f[i] = 1;
            } else {
                move_outside(i);
            }
        }
        if (in == mi * cnt) {
            for (int i = 0; i < N; i++) {
                if (f[i]) {
                    blocked[i] = 1;
                }
            }
            lo = mi;
        } else {
            hi = in / cnt;
            for (int i = 0; i < N; i++) {
                if (!f[i]) {
                    blocked[i] = 1;
                }
                if (blocked[i]) {
                    continue;
                }
                if (f[i]) {
                    f[i] = 0;
                    in--;
                    move_outside(i);
                }
            }
        }
    }
    return lo;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:22:41: warning: unused variable 'ad' [-Wunused-variable]
   22 |     int lo = 1, hi = N / cnt, in = cnt, ad = 1;
      |                                         ^~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 74.89 / 75