Submission #828366

#	Time	Username	Problem	Language	Result	Execution time	Memory
828366		tomruk	Counting Mushrooms (IOI20_mushrooms)	C++17	88.28 / 100	11 ms	344 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;

int count_mushrooms(int n) {
	vector<int> a = {0},b;
	int last = 1;
	int th = 0;
	int val = 1e9;
	for(int i = 1;i<n;i++){
		if(i + n/i < val){
			th = i;
			val = i + n/i;
		}
	}
	while(last < n && max(a.size(),b.size()) < th){
		if(last  + 1 == n || max(a.size(),b.size()) == 1){
			int num = use_machine({0,last});
			if(num == 0)
				a.push_back(last);
			else b.push_back(last);
			last++;
		}
		else{
			if(a.size() > b.size()){
				int num = use_machine({last,a[0],last+1,a[1]});
				if(num & 1){
					b.push_back(last);
				}
				else a.push_back(last);
				if(num & 2){
					b.push_back(last + 1);
				}
				else a.push_back(last + 1);
				last+=2;
			}
			else{
				int num = use_machine({last,b[0],last+1,b[1]});
				if(num & 1){
					a.push_back(last);
				}
				else b.push_back(last);
				if(num & 2){
					a.push_back(last + 1);
				}
				else b.push_back(last + 1);
				last+=2;
			}
		}
	}
	int ca = 0,cb = 0;
	while(last < n){
		if(a.size() > b.size()){
			int cnt = 0;
			vector<int> ask;
			while(cnt < a.size() && last < n){
				ask.push_back(last);
				ask.push_back(a[cnt]);
				cnt++;
				last++;
			}
			int num = use_machine(ask);
			ca += cnt;
			ca -= num/2;
			ca -= num&1;
			if(num & 1){
				b.push_back(last - cnt);
			}
			else{
				a.push_back(last - cnt);
				ca--;
			}
		}
		else{
			int cnt = 0;
			vector<int> ask;
			while(cnt < b.size() && last < n){
				ask.push_back(last);
				ask.push_back(b[cnt]);
				cnt++;
				last++;
			}
			int num = use_machine(ask);
			ca += num/2;
			ca += num&1;
			if(num & 1){
				a.push_back(last - cnt);
				ca--;
			}
			else b.push_back(last - cnt);
		}
	}
	return a.size() + ca;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:16:43: warning: comparison of integer expressions of different signedness: 'const long unsigned int' and 'int' [-Wsign-compare]
   16 |  while(last < n && max(a.size(),b.size()) < th){
      |                    ~~~~~~~~~~~~~~~~~~~~~~~^~~~
mushrooms.cpp:56:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |    while(cnt < a.size() && last < n){
      |          ~~~~^~~~~~~~~~
mushrooms.cpp:77:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   77 |    while(cnt < b.size() && last < n){
      |          ~~~~^~~~~~~~~~
mushrooms.cpp:51:13: warning: unused variable 'cb' [-Wunused-variable]
   51 |  int ca = 0,cb = 0;
      |             ^~

• Subtask 1: 88.2812 / 100