Submission #1313815

#	Time	Username	Problem	Language	Result	Execution time	Memory
1313815		BigBadBully	Counting Mushrooms (IOI20_mushrooms)	C++20	90.76 / 100	3 ms	504 KiB

mushrooms

#include <bits/stdc++.h>
#include "mushrooms.h"
using namespace std;
const int inf = 1e9;
#define pii pair<int,int>
#define ff first
#define ss second
int count_mushrooms(int n) {
	int bl = 115;
	vector<int> v(n,1);
	v[0] = 0;
	bool dif = 0;
	int st = 1;
	vector<int> wh[2];
	wh[0].push_back(0);
	function<void()> nxt = [&]()
	{
		int mxx =max(wh[0].size(),wh[1].size());
		if(mxx>=2 && st < n-1)
		{
			for(int it = 0;it < 2; it++)
				if(wh[it].size()==mxx)
				{
					int x = use_machine({wh[it][0],st+1,wh[it][1],st});
					v[st]=(x&1)^(it);
					wh[v[st]].push_back(st);
					v[++st]=((x&2)/2)^(it);
					wh[v[st]].push_back(st);
					break;
				}
		}
		else
		{
			v[st] = use_machine({st-1,st})^v[st-1];
			wh[v[st]].push_back(st);
		}
	};
	for(;st<n;st++)
	{
		nxt();
		if(max(wh[0].size(),wh[1].size())>=bl)
			break;
	}
	st++;
	
	int sum = count(v.begin(),v.end(),0);
	function<int(int,int)> calc = [&](int l,int r)
	{
		vector<int> que;
		array<int,2> idx = {0,0};
		bool gurt = 0;
		int dom = 0;
		function<void()>f = [&](){
			for(int it = 0;it < 2;it++)
				if(wh[it].size()==max(wh[0].size(),wh[1].size()))
				{
					dom = it;
					que.push_back(wh[it][idx[it]++]);
					break;
				}
		};
		
		for(int i = l; i <= r; i++)
		{
			f();
			que.push_back(i);
		}
		int rl = use_machine(que);
		int val = (rl+1)/2;
		int len = r-l+1;
		wh[(rl%2)^(wh[1].size()>wh[0].size())].push_back(r);
		if(dom)
			return val;
		return len-val;
	};

	for(int plus = max(wh[0].size(),wh[1].size());st<n;st+=plus)
		plus=max(wh[0].size(),wh[1].size()),
		sum+=calc(st,min<int>(st+max(wh[0].size(),wh[1].size())-1,n-1));
	
	return sum;
}

• Subtask 1: 90.7631 / 100