Submission #354450

#	Time	Username	Problem	Language	Result	Execution time	Memory
354450		amunduzbaev	Counting Mushrooms (IOI20_mushrooms)	C++14	79.86 / 100	10 ms	492 KiB

mushrooms

#include "mushrooms.h"
#ifndef EVAL
#include "stub.cpp"
#endif
#include <bits/stdc++.h>
using namespace std;
 
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(),x.rend()
#define fastios ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define vll vector<ll>
#define vii vector<int>
#define vpii vector<pii>
#define vpll vector<pll>
#define cnt(a)__builtin_popcount(a)
template<class T> bool umin(T& a, const T& b) {return a > b? a = b, true:false;}
template<class T> bool umax(T& a, const T& b) {return a < b? a = b, true:false;}
 
const int N = 2e3+5;
const int mod = 1e9+7;
const ll inf = 1e18;
const ld Pi = acos(-1);

vector<int> a, b;
int i, B = 143, nn;

void find(){
	i = 1;
	a.pb(0);
	while(sz(a) < 2 && sz(b) < 2 && i < nn){
		if(!use_machine({0, i})) a.pb(i);
		else b.pb(i);
		i++;
	}
	if(sz(a) > sz(b)){
		while(sz(a) < B && sz(b) < B && i + 1 < nn){
			vii tt = {a[0], i, a[1], i+1};
			int res = use_machine(tt);
			if(res == 0){
				a.pb(i);
				a.pb(i+1);
			}if(res == 1){
				a.pb(i);
				b.pb(i+1);
			}if(res == 2){
				a.pb(i+1);
				b.pb(i);
			}if(res == 3){
				b.pb(i+1);
				b.pb(i);
			}i+=2;
		}
	}else{
		while(sz(a) < B && sz(b) < B && i + 1 < nn){
			vii tt = {b[0], i, b[1], i+1};
			int res = use_machine(tt);
			if(res == 0){
				b.pb(i);
				b.pb(i+1);
			}if(res == 1){
				b.pb(i);
				a.pb(i+1);
			}if(res == 2){
				b.pb(i+1);
				a.pb(i);
			}if(res == 3){
				a.pb(i+1);
				a.pb(i);
			}i+=2;
		}
	}
	
	//cout<<"A"<<endl;
	//for(auto x:a) cout<<x<<" ";
	//cout<<endl<<"____________________________________"<<endl;
	//cout<<endl<<"B"<<endl;
	//for(auto x:b) cout<<x<<" ";
	//cout<<endl<<"____________________________________"<<endl;
}

int count_mushrooms(int n){
	nn = n;
	find();
	
	if(i == n-1){
		if(!use_machine({0, i})) a.pb(i);
		else b.pb(i);
		i++;
	}
	int ans = sz(a);
	while(i < n){
		if(sz(a) > sz(b)){
			vii tmp;
			int cnt = 0;
			for(auto x:a){
				tmp.pb(x);
				tmp.pb(i);
				i++, cnt++;
				if(i >= n) break;
			}
			
			i--, cnt--, tmp.pop_back();
			
			int res = use_machine(tmp);
			
			//if(res%2) b.pb(i-1);
			//else a.pb(i-1);
			
			res /= 2;
			ans += (cnt - res);
		}
		
		else{
			vii tmp;
			for(auto x:b){
				tmp.pb(x);
				tmp.pb(i);
				i++;
				if(i >= n) break;
			}
			
			i--, tmp.pop_back();
			
			int res = use_machine(tmp);
			
			//if(res%2) a.pb(i-1);
			//else b.pb(i-1); 
			
			res /= 2;
			ans += res;
		}
		
		if(i == n-1){
			if(!use_machine({0, i})) { a.pb(i); ans++; }
			else b.pb(i);
			i++;
		}
	}
	
	return ans;
}

• Subtask 1: 79.8587 / 100