Submission #627936

#	Time	Username	Problem	Language	Result	Execution time	Memory
627936		tutis	Rarest Insects (IOI22_insects)	C++17	57.18 / 100	199 ms	63108 KiB

insects

#include "insects.h"
#include <bits/stdc++.h>
using namespace std;
int min_cardinality(vector<int> x)
{
    int N = x.size();
    int add2 = 0;
    int add1 = 0;
    vector<int>y;
    int lo, hi;
    auto cnt = [&](int c)->int
    {
        vector<int>v;
        y = {};
        int k = 0;
        for (int i : x)
        {
            v.push_back(i);
            move_inside(i);
            k = press_button();
            if (k + add1 == c + 1)
            {
                v.pop_back();
                move_outside(i);
                y.push_back(i);
            }
        }
        int r = v.size();
        for (int i : v)
            move_outside(i);
        return add2 + r;
    };
    int c = cnt(1);
    if (c * 2 > N)
        return 1;
    {
        x = y;
        add2 = c;
        add1 = 1;
    }
    lo = 1;
    hi = N / c;
    double bias = 3.2;
    vector<vector<pair<double, int>>>dp(hi + 1, vector<pair<double, int>>(hi + 1));
    for (int sz = 1; sz <= hi; sz++)
    {
        for (int l = 1; l + sz - 1 <= hi; l++)
        {
            int r = l + sz - 1;
            if (sz == 1)
                dp[l][r] = {0, l};
            else
            {
                int m0 = l + 1;
                int m1 = r;
                int m = round((l * bias + r * 1.0) / (bias + 1));
                auto f = [&](int x)
                {
                    x = max(x, l + 1);
                    x = min(x, r);
                    return max(dp[l][x - 1].first, dp[x][r].first);
                };
                for (int x = dp[l][r - 1].second; x <= dp[l + 1][r].second; x++)
                {
                    if (f(x) <= f(m))
                        m = x;
                }
                m = max(m, l + 1);
                m = min(m, r);
                dp[l][r].first = f(m) + N - lo * c;
                dp[l][r].second = m;
            }
        }
    }
    while (lo < hi)
    {
        int m = dp[lo][hi].second;
        if (hi - lo + 1 >= 64)
            m = round((lo * bias + hi * 1.0) / (bias + 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
            hi = m - 1;
    }
    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);
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(std::vector<int>)':
insects.cpp:54:21: warning: unused variable 'm0' [-Wunused-variable]
   54 |                 int m0 = l + 1;
      |                     ^~
insects.cpp:55:21: warning: unused variable 'm1' [-Wunused-variable]
   55 |                 int m1 = r;
      |                     ^~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 32.18 / 75