Submission #742107

#	Time	Username	Problem	Language	Result	Execution time	Memory
742107		fanwen	Rarest Insects (IOI22_insects)	C++17	100 / 100	64 ms	456 KiB

insects

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

using namespace std;

#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()

#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(it, s) for (__typeof(s.begin()) it = (s).begin(); it != (s).end(); ++it)

template <class U, class V> bool maximize(U &A, const V &B) { return (A < B) ? (A = B, true) : false; }
template <class U, class V> bool minimize(U &A, const V &B) { return (A > B) ? (A = B, true) : false; }

mt19937 jdg(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int l, int r) { return l + jdg() % (r - l + 1); }

vector <int> insects;
int min_cardinality(int n) {
    insects.assign(n, 0); iota(ALL(insects), 0);
    shuffle(ALL(insects), jdg);
    int cnt = 0;
    vector <int> remain;
    REP(i, n) {
        move_inside(insects[i]);
        if(press_button() > 1) {
            move_outside(insects[i]);
            remain.push_back(insects[i]);
        } else cnt++;
    }
    if(cnt == 1) return n;
    if(cnt == 2) {
        REP(i, n) move_inside(insects[i]);
        return n - press_button();
    }
    int l = 2, r = n / cnt, last = 1, ans = 1;
    while(r >= l) {
        int mid = l + r >> 1;
        vector <int> new_remain, removing;
        int res = 0, id = 0;
        for (auto &x : remain) {
            ++id;
            move_inside(x);
            if(press_button() > mid) {
                move_outside(x);
                new_remain.push_back(x);
            } else res++, removing.push_back(x);
            if(res == cnt * (mid - last)) {
                FOR(i, id, (int) remain.size() - 1) new_remain.push_back(remain[i]);
                break;
            }
        }
        if(res == cnt * (mid - last)) {
            ans = last = mid;
            l = mid + 1;
            swap(remain, new_remain);
        } else {
            r = mid - 1;
            for (auto x : removing) move_outside(x);
            swap(remain, removing);
        }
    }
    return ans;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:42:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   42 |         int mid = l + r >> 1;
      |                   ~~^~~

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