Submission #627955

#	Time	Username	Problem	Language	Result	Execution time	Memory
627955		tutis	Rarest Insects (IOI22_insects)	C++17	53.76 / 100	460 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;
    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;
    }
    double bias = 3.2;
    int mx = N / c;
    vector<vector<pair<double, int>>>dp(mx + 1, vector<pair<double, int>>(mx + 1, {0.0, 0}));
    for (int sz = 2; sz <= mx; sz++)
    {
        for (int l = 1; l + sz - 1 <= mx; l++)
        {
            int r = l + sz - 1;
            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);
            };
            if (sz <= 50)
                for (int x = l + 1; x <= r; x++)
                {
                    if (f(x) <= f(m))
                        m = x;
                }
            else
                for (int x = dp[l][r - 1].second - 5; x <= dp[l + 1][r].second + 5; x++)
                {
                    if (f(x) <= f(m))
                        m = x;
                }
            m = max(m, l + 1);
            m = min(m, r);
            dp[l][r].first = f(m) + N - l * c;
            dp[l][r].second = m;
        }
    }
    int lo = 1;
    int hi = N / c;
    while (lo < hi)
    {
        int m = dp[lo][hi].second;
        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:48:17: warning: unused variable 'm0' [-Wunused-variable]
   48 |             int m0 = l + 1;
      |                 ^~
insects.cpp:49:17: warning: unused variable 'm1' [-Wunused-variable]
   49 |             int m1 = r;
      |                 ^~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 28.76 / 75