Submission #834861

#	Time	Username	Problem	Language	Result	Execution time	Memory
834861		esomer	Rarest Insects (IOI22_insects)	C++17	Compilation error	0 ms	0 KiB

insects

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

using namespace std;

mt19937 gen(time(0));

int groups, lft;
vector<bool> done;

int get_groups(int N){
	int groups = 0;
	for(int i = 0; i < N; i++){
		move_inside(i);
		int rep = press_button();
		if(rep > 1) { move_outside(i); }
		else { groups++; done[i] = 1; }
	}
	return groups;
}

int choose_best(int lo, int hi){
	//If I choose mid. Then in the case that all the groups are of size at least mid,
	//I discard (mid - lo + 1) * groups.
	//In the other case, I discard left - chosen (and chosen can be at most (mid - lo + 1) * groups).
	//So I want min((mid - lo + 1) * groups, left - (mid - lo + 1) * groups) to be the maximum.
	int x = lft / 2;
	int bst = x / groups;
	int mn1 = min(bst * groups, lft - bst * groups + 1);
	bst++;
	int mn2 = min(bst * groups, lft - bst * groups + 1);
	if(mn1 < mn2) bst--;
	return max(lo, min(hi, lo + bst - 1));
}

int min_cardinality(int N) {
	done.assign(N, 0);
	int ans = 1;
	groups = get_groups(N);
	lft = N - groups;
	int cnt = groups;
	int lo = 2;
	int hi = N / groups;
	while(lo <= hi && lft > 0) {
		int mid = choose_best(lo, hi);
		vector<int> good, bad;
		vector<int> possible;
		for(int i = 0; i < N; i++) {
			if(!done[i]) possible.push_back(i);
		}
		while((int)possible.size() > 0){
			if((cnt + (int)good.size()) == mid * groups) {
				bad.push_back(possible.back());
				possible.pop_back();
				continue;
			}
			int ind = gen() % ((int)possible.size());
			int i = possible[ind];
			move_inside(i);
			int rep = press_button();
			if(rep > mid) {
				bad.push_back(i);
				move_outside(i);
			} else { good.push_back(i); }
			if(ind != (int)possible.size() - 1) swap(possible[ind], possible[(int)possible.size() - 1]);
			possible.pop_back();
		}
		if((int)good.size() + cnt == mid * groups) {
			ans = mid;
			lo = mid + 1;
			for(int x : good) done[x] = 1;
			cnt += (int)good.size();
			lft -= (int)good.size();
		} else {
			hi = mid - 1;
			for(int x : good) move_outside(x);
			for(int x : bad) done[x] = 1;
			lft -= (int)bad.size();
		}
	}
	return ans;
}

static constexpr int kMaxQueries = 40000;

static int N;
// Insect types are compressed to colors in the range [0, N).
static std::vector<int> color;
static std::vector<bool> in_box;

static std::vector<int> color_occurrences;
static std::multiset<int> max_occurrences;

static std::vector<int> op_counter(3, 0);

static void protocol_violation(std::string message) {
  printf("Protocol Violation: %s\n", message.c_str());
  exit(0);
}

void move_inside(int i) {
  if (i < 0 || i >= N) {
    protocol_violation("invalid parameter");
  }
  ++op_counter[0];
  if (op_counter[0] > kMaxQueries) {
    protocol_violation("too many calls");
  }
  if (!in_box[i]) {
    in_box[i] = true;
    max_occurrences.erase(max_occurrences.find(color_occurrences[color[i]]));
    ++color_occurrences[color[i]];
    max_occurrences.insert(color_occurrences[color[i]]);
  }
}

void move_outside(int i) {
  if (i < 0 || i >= N) {
    protocol_violation("invalid parameter");
  }
  ++op_counter[1];
  if (op_counter[1] > kMaxQueries) {
    protocol_violation("too many calls");
  }
  if (in_box[i]) {
    in_box[i] = false;
    max_occurrences.erase(max_occurrences.find(color_occurrences[color[i]]));
    --color_occurrences[color[i]];
    max_occurrences.insert(color_occurrences[color[i]]);
  }
}

int press_button() {
  ++op_counter[2];
  if (op_counter[2] > kMaxQueries) {
    protocol_violation("too many calls");
  }
  return *(max_occurrences.rbegin());
}

int main() {
  assert(1 == scanf("%d", &N));
  color.resize(N);
  in_box.assign(N, false);

  std::map<int, int> type_to_color;
  for (int i = 0; i < N; ++i) {
    int Ti;
    assert(1 == scanf("%d", &Ti));
    if (type_to_color.find(Ti) == type_to_color.end()) {
      int new_color = type_to_color.size();
      type_to_color[Ti] = new_color;
      max_occurrences.insert(0);
    }
    color[i] = type_to_color[Ti];
  }

  color_occurrences.assign(type_to_color.size(), 0);

  int answer = min_cardinality(N);
  int Q = *std::max_element(op_counter.begin(), op_counter.end());
  printf("%d\n", answer);
  printf("%d\n", Q);
  return 0;
}

Compilation message (stderr)

/usr/bin/ld: /tmp/cceWgTnH.o: in function `move_inside(int)':
stub.cpp:(.text+0x0): multiple definition of `move_inside(int)'; /tmp/ccONUdJH.o:insects.cpp:(.text+0x2f0): first defined here
/usr/bin/ld: /tmp/cceWgTnH.o: in function `move_outside(int)':
stub.cpp:(.text+0xe0): multiple definition of `move_outside(int)'; /tmp/ccONUdJH.o:insects.cpp:(.text+0x4c0): first defined here
/usr/bin/ld: /tmp/cceWgTnH.o: in function `press_button()':
stub.cpp:(.text+0x1c0): multiple definition of `press_button()'; /tmp/ccONUdJH.o:insects.cpp:(.text+0x260): first defined here
/usr/bin/ld: /tmp/cceWgTnH.o: in function `main':
stub.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccONUdJH.o:insects.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status