Submission #1051706

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051706		TahirAliyev	Counting Mushrooms (IOI20_mushrooms)	C++17	0 / 100	19 ms	344 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define ll long long
#define all(v) v.begin(), v.end()
#define oo 1e9
const int B = 200;

int count_mushrooms(int n){
	int ans = 0, cur = 0, t = 0;
	vector<int> id;
	for(int i = 0; i < n; i++) id.push_back(i);
	random_shuffle(id.begin() + 1, id.end());
	vector<int> one;
	while(one.size() < B && cur + 1 < n){
		vector<int> v;
		for(int i = cur; i < min(cur + B, n); i++) v.push_back(id[i]);
		if(!use_machine(v)){
			if(t) for(int i = cur; i < min(cur + B, n); i++) one.push_back(i);
			else ans += v.size();
			t ^= 1;
			cur += B;
			continue;
		}
		int l = cur, r = min(cur + B, n) - 1;
		while(l < r){
			int mid = (l + r + 1) / 2;
			vector<int> v;
			for(int i = l; i <= mid; i++) v.push_back(id[i]);
			if(!use_machine(v)) l = mid;
			else r = mid - 1;
		}
		if(t) for(int i = cur; i <= l; i++) one.push_back(i);
		else ans += l - cur + 1;
		t ^= 1;
		cur = l + 1;
	}
	if(cur == n - 2){
		ans += (t == 0);
		cur++;
	}
	while(cur < n){
		vector<int> v;
		for(int i = 0; i < one.size() && cur < n; i++, cur++){
			v.push_back(id[one[i]]);
			v.push_back(id[cur]);
		}
		ans += (use_machine(v) + 1) / 2;
	}
	return ans;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:45:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   for(int i = 0; i < one.size() && cur < n; i++, cur++){
      |                  ~~^~~~~~~~~~~~

• Subtask 1: 0 / 100