Submission #1075182

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075182		Zicrus	Rarest Insects (IOI22_insects)	C++17	64.49 / 100	96 ms	932 KiB

insects

#include <bits/stdc++.h>
#include "insects.h"
using namespace std;
 
typedef long long ll;
 
int n;
vector<bool> in;
unordered_set<int> s;
int cnt;
 
int add(int i) {
    if (in[i]) return 0;
    move_inside(i);
    cnt++;
    in[i] = true;
    return 1;
}
 
int remove(int i) {
    if (!in[i]) return 0;
    move_outside(i);
    cnt--;
    in[i] = false;
    return 1;
}
 
int min_cardinality(int N) {
    n = N;
    cnt = 0;
    mt19937 mt(time(0));
    in = vector<bool>(n);
    for (int i = 0; i < n; i++) {
        add(i);
    }
    int mx = press_button();
    int prevSz = cnt;
    while (mx > 1) {
        int cur = mx;
        while (cur == mx) {
            int i = mt()%n;
            while (!remove(i)) i = mt()%n;
            int j = mt()%n;
            while (!remove(j)) j = mt()%n;
            cur = press_button();
            if (cur == mx) {
                s.insert(i);
                s.insert(j);
            }
            else {
                add(j);
                cur = press_button();
                if (cur == mx) {
                    s.insert(i);
                    remove(j);
                }
                cur = mx-1;
            }
        }
        for (auto &e : s) {
            if (add(e)) {
                cur = press_button();
                if (cur == mx) remove(e);
            }
        }
        if (cnt * mx % (mx-1) == 0 && cnt * mx / (mx-1) == prevSz) {
            break;
        }
        s.clear();
        prevSz = cnt;
        mx--;
    }
    return mx;
} 
 
#ifdef TEST
#include "grader.cpp"
#endif

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 39.49 / 75