Submission #726361

#	Time	Username	Problem	Language	Result	Execution time	Memory
726361		aykhn	Rarest Insects (IOI22_insects)	C++17	99.95 / 100	61 ms	420 KiB

insects

#include <bits/stdc++.h>
#include "insects.h"

using namespace std;

typedef long long ll;

#define OPT ios_base::sync_with_stdio(0); \
            cin.tie(0); \
            cout.tie(0)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define all(v) v.begin(), v.end()
#define mpr make_pair
#define pb push_back
#define ts to_string
#define fi first
#define se second
#define inf 0x3F3F3F3F
#define infll 0x3F3F3F3F3F3F3F3FLL
#define bpc __builtin_popcount
#define print(v) for(int i = 0; i < v.size(); i++) cout << v[i] << " "; cout<<endl;

int min_cardinality(int n)
{

    int sz = 0;

    vector<int> out;

    for (int i = 0; i < n; i++)
    {
        move_inside(i);
        int x = press_button();
        if (x > 1)
        {
            move_outside(i);
            out.pb(i);
        }
        else sz++;
    }

    int best = 1;
    int rn = sz;
    int l = 2;
    int r = n/sz;

    while (l <= r)
    {
        int mid = (l + r) >> 1;
        vector<int> temp;
        vector<int> nout;

        for (int i = 0; i < out.size(); i++)
        {
            if (rn == mid * sz)
            { // fill out to next out (nout)
                for (int j = i; j < out.size(); j++) nout.pb(out[j]);
                break;
            }
            move_inside(out[i]);

            int x = press_button();

            if (x > mid)
            {
                nout.pb(out[i]);
                move_outside(out[i]);
            }
            else
            {
                rn++;
                temp.pb(out[i]);
            }
        }
 // if true, previous elements not needed
 // current elements not needed ?? yes
 // (*) extras not needed (nout) if min is already lower <- important

        if (rn == mid * sz)
        {
            best = max(best, mid);
            l = mid + 1;
            out = nout;
        }
        else
        {
            r = mid - 1;
            rn -= (int)(temp.size());
            for (int x : temp)
            {
                move_outside(x);
            }
            out = temp; // (*) <-
        }
    }

    return best;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:54:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |         for (int i = 0; i < out.size(); i++)
      |                         ~~^~~~~~~~~~~~
insects.cpp:58:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |                 for (int j = i; j < out.size(); j++) nout.pb(out[j]);
      |                                 ~~^~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 74.95 / 75