Submission #824549

#	Time	Username	Problem	Language	Result	Execution time	Memory
824549		ymm	Counting Mushrooms (IOI20_mushrooms)	C++17	80.71 / 100	7 ms	464 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (r); ++x)
typedef long long ll;
typedef std::pair<ll,ll> pll;
using namespace std;

vector<int> A, B, U;
int CNT = 0;
int use_my_machine(vector<int> vec) {
	int res = use_machine(vec);
	++CNT;
	return res;
}
#define use_machine use_my_machine

void query1()
{
	if (!U.size())
		return;
	int x = U.back();
	U.pop_back();
	(use_machine({0, x})? B: A).push_back(x);
}
void query2()
{
	if (U.size() < 2 || (A.size() < 2 && B.size() < 2))
		return query1();
	int x = U.back(); U.pop_back();
	int y = U.back(); U.pop_back();
	if (A.size() >= 2) {
		int res = use_machine({A[0], x, A[1], y});
		int a = res/2;
		int b = res%2;
		(a? B: A).push_back(x);
		(b? B: A).push_back(y);
	} else {
		int res = use_machine({B[0], x, B[1], y});
		int a = res/2;
		int b = res%2;
		(a? A: B).push_back(x);
		(b? A: B).push_back(y);
	}
}
void queryx(vector<int> &A, vector<int> &B)
{
	int u[5];
	Loop (i,0,3) {
		u[i] = U.back();
		U.pop_back();
	}
	int res = use_machine({u[0], A[0], u[1], A[1], u[2], A[2]});
	int r0 = res&1; res -= r0;
	(r0? B: A).push_back(u[0]);
	if (res == 0) {
		A.push_back(u[1]);
		A.push_back(u[2]);
		return;
	}
	if (res == 4) {
		B.push_back(u[1]);
		B.push_back(u[2]);
		return;
	}
	Loop (i,3,5) {
		u[i] = U.back();
		U.pop_back();
	}
	res = use_machine({u[3], A[0], u[4], A[1], u[1], A[2], B[0], u[2], B[1]});
	res -= 1;
	int r3 = res/1%2;
	int r4 = res/2%2;
	int r12 = res/4%2;
	(r3? B: A).push_back(u[3]);
	(r4? B: A).push_back(u[4]);
	(r12? B: A).push_back(u[1]);
	(r12? A: B).push_back(u[2]);
}
int try_now()
{
	int cnt = A.size() + B.size();
	int rem = U.size();
	int ans = 0;
	while (rem > 0) {
		int x = max<int>(max(A.size(), B.size()), (cnt+1)/2);
		x = min(x, rem);
		rem -= x;
		++cnt;
		++ans;
		return ans;
	}
	return ans;
}
int other_A = 0;
void queryline()
{
	if (!U.size())
		return;
	auto &C = A.size() > B.size()? A: B;
	int cnt = min(C.size(), U.size());
	vector<int> vec;
	int lst = -1;
	Loop (i,0,cnt) {
		vec.push_back(C[i]);
		vec.push_back(U.back());
		lst = U.back();
		U.pop_back();
	}
	int res = use_machine(vec);
	int rl = res&1;
	if (A.size() > B.size()) {
		other_A += cnt-1-res/2;
		(rl? B: A).push_back(lst);
	} else {
		other_A += res/2;
		(rl? A: B).push_back(lst);
	}
}

int count_mushrooms(int n) {
	A.clear(); U.clear(); B.clear(); other_A = 0;
	CNT = 0;
	A.push_back(0);
	Loop (i,1,n)
		U.push_back(i);
	while (CNT + try_now() > 250) {
		query2();
	}
	while (U.size())
		queryline();
	return A.size() + other_A;
}

• Subtask 1: 80.7143 / 100