Submission #627977

#	Time	Username	Problem	Language	Result	Execution time	Memory
627977		tutis	Rarest Insects (IOI22_insects)	C++17	83.70 / 100	120 ms	440 KiB

insects

#include "insects.h"
#include <bits/stdc++.h>
using namespace std;
mt19937_64 rng(2);
int min_cardinality(vector<int> x)
{
    shuffle(x.begin(), x.end(), rng);
    int N = x.size();
    int add2 = 0;
    int add1 = 0;
    vector<int>y;
    int lo, hi;
    int c = 0;
    auto cnt = [&](int m)->int
    {
        vector<int>v;
        y = {};
        int k = 0;
        bool jau = false;
        int liko = (int)x.size();
        for (int i : x)
        {
            if (!jau)
                v.push_back(i);
            if (!jau)
                move_inside(i);
            if (!jau)
                k = press_button();
            if (k + add1 == m + 1 || jau)
            {
                if (!jau)
                    v.pop_back();
                if (!jau)
                    move_outside(i);
                y.push_back(i);
            }
            liko--;
            if (c != 0)
                if ((int)v.size() + add2 == m * c)
                    jau = true;
            if (c != 0)
                if ((int)v.size() + add2 + liko < m * c)
                    jau = true;
        }
        int r = v.size();
        for (int i : v)
            move_outside(i);
        return add2 + r;
    };
    c = cnt(1);
    if (c * 2 > N)
        return 1;
    {
        x = y;
        add2 = c;
        add1 = 1;
    }
    lo = 1;
    hi = N / c;
    double bias = 3.5;
    bool fst = true;
    while (lo < hi)
    {
        int m = round((lo * bias + hi * 1.0) / (bias + 1));
        if (fst)
            m = round((lo * 2 + hi * 1.0) / (2 + 1));
        m = max(m, lo + 1);
        m = min(m, hi);
        int k = cnt(m);
        if (k == m * c)
        {
            lo = m;
            x = y;
            add2 = m * c;
            add1 = m;
        }
        else
        {
            if (k == m * c - 1)
                return m - 1;
            hi = m - 1;
        }
        fst = false;
    }
    return lo;
}
int min_cardinality(int N) {
    vector<int>v;
    for (int i = 0; i < N; i++)
        v.push_back(i);
    return min_cardinality(v);
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 58.7 / 75