Submission #430552

#	Time	Username	Problem	Language	Result	Execution time	Memory
430552		alishahali1382	Counting Mushrooms (IOI20_mushrooms)	C++14	92.62 / 100	14 ms	456 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
#pragma GCC optimize("O2")
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
#define debug(x) {cerr<<#x<<"="<<x<<"\n";}
#define debug2(x, y) {cerr<<"{"<<#x<<", "<<#y<<"}={"<<x<<", "<<y<<"}\n";}
#define debugp(p) {cerr<<#p<<"={"<<p.first<<", "<<p.second<<"}\n";}
#define debugv(abcd) {cerr<<#abcd<<": "; for (auto dcba:abcd) cerr<<dcba<<", ";cerr<<"\n";}
#define pb push_back
#define all(x) x.begin(), x.end()
#define SZ(x) ((int)x.size())

const int inf=1000000100; // 1e9
const ll INF=10000000001000000; // 1e16
const int mod=1000000007;
const int MAXN=20010;

int n, m, k, x, y, a, b, t=80, ans;
vi A, B;

inline int ask(vi vec){ return use_machine(vec);}
int Solve(vi vec){
	if (SZ(A)>=SZ(vec)){
		vi shit;
		for (int i=0; i<SZ(vec); i++){
			shit.pb(A[i]);
			shit.pb(vec[i]);
		}
		// shit.pb(A[SZ(vec)]);
		int res=ask(shit);
		if (res&1) B.pb(shit.back());
		else A.pb(shit.back());
		return SZ(vec)-(res+1)/2;
	}
	vi shit;
	for (int i=0; i<SZ(vec); i++){
		shit.pb(B[i]);
		shit.pb(vec[i]);
	}
	// shit.pb(B[SZ(vec)]);
	int res=ask(shit);
	if (res&1) A.pb(shit.back());
	else B.pb(shit.back());
	return (res+1)/2;
}

int count_mushrooms(int _n){
	n=_n;
	if (n<400){ // wtf am I doing?
		ans=1;
		for (int i=1; i<n; i+=2){
			if (i==n-1){
				ans+=1-ask({0, i});
				continue ;
			}
			ans+=2-ask({i, 0, i+1});
		}
		return ans;
	}
	int pos=0;
	bool rev=0;
	
	A.pb(pos++);
	while (pos<3){
		int i=pos++;
		if (ask({0, i})) B.pb(i);
		else A.pb(i);
	}
	if (SZ(A)<2){
		A.swap(B);
		rev=1;
	}
	assert(SZ(A)>=2);
	for (int i=pos; max(SZ(A), SZ(B))<t; i+=2, pos+=2){
		int tmp=ask({i, A[0], i+1, A[1]});
		if (tmp&1) B.pb(i);
		else A.pb(i);
		if (tmp&2) B.pb(i+1);
		else A.pb(i+1);
	}
	if (rev) A.swap(B);

	// assert(max(SZ(A), SZ(B))>=t);
	ans=SZ(A);
	for (int i=pos; i<n; ){
		vi vec;
		while(SZ(vec)<max(SZ(A), SZ(B)) && i<n)
			vec.pb(i++);
		// debugv(vec)
		ans+=Solve(vec);
	}
	return ans;
}

• Subtask 1: 92.623 / 100