Submission #635333

#	Time	Username	Problem	Language	Result	Execution time	Memory
635333		marvinthang	Rarest Insects (IOI22_insects)	C++17	100 / 100	66 ms	1312 KiB

insects

/*************************************
*    author: marvinthang             *
*    created: 25.08.2022 22:19:29    *
*************************************/

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

using namespace std;

#define                  fi  first
#define                  se  second
#define                 div  ___div
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define             FULL(i)  (MASK(i) - 1)
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#define          file(name)  if (fopen (name".inp", "r")) { freopen (name".inp", "r", stdin); freopen (name".out", "w", stdout); }

template <class T>             scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class T>            print_op(vector <T>)  { out << '{'; for (size_t i = 0; i + 1 < u.size(); ++i) out << u[i] << ", "; if (!u.empty()) out << u.back(); return out << '}'; }
template <class U, class V>   scan_op(pair <U, V>)  { return in >> u.fi >> u.se; }
template <class U, class V>  print_op(pair <U, V>)  { return out << '(' << u.fi << ", " << u.se << ')'; }

const double PI = 3.1415926535897932384626433832795; // acos(-1.0); atan(-1.0);
const int dir[] = {1, 0, -1, 0, 1, 1, -1, -1, 1}; // {2, 1, -2, -1, -2, 1, 2, -1, 2};

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); 
long long rand(long long l, long long h) { return uniform_int_distribution <long long> (l, h) (rng); } 

set <int> insides;
vector <int> order;

void add(int i) {
	move_inside(order[i]);
	insides.insert(i);
}

void remove(int i) {
	move_outside(order[i]);
	insides.erase(i);
}

void reset_machine(void) {
	set <int> tmp = insides;
	for (int i: tmp) remove(i);
}

int min_cardinality(int n) {
	order.resize(n);
	iota(order.begin(), order.end(), 0);
	shuffle(order.begin(), order.end(), rng);
	for (int i = 0; i < n; ++i) {
		add(i);
		if (press_button() > 1) remove(i);
	}
	map <int, set <int>> machine_states;
	machine_states[1] = insides;
	for (int i = 0; i < n; ++i) machine_states[n].insert(i);
	int unique_vals = insides.size();
	int l = 2, r = n / unique_vals;
	while (l <= r) {
		int m = l + r >> 1;
		auto it = machine_states.lower_bound(m);
		set <int> just_added;
		for (int i: it->se) if (!insides.count(i)) {
			add(i);
			if (press_button() > m) remove(i);
			else just_added.insert(i);
			if (insides.size() >= unique_vals * m) break;
		}
		int total = insides.size();
		machine_states[m] = insides;
		if (total >= unique_vals * m) l = m + 1;
		else {
			r = m - 1;
			for (int i: just_added) remove(i);
		}
	}
	return r;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:68:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   68 |   int m = l + r >> 1;
      |           ~~^~~
insects.cpp:75:23: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   75 |    if (insides.size() >= unique_vals * m) break;
      |        ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~

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