Submission #702087

#	Time	Username	Problem	Language	Result	Execution time	Memory
702087		grossly_overconfident	Counting Mushrooms (IOI20_mushrooms)	C++17	91.87 / 100	8 ms	336 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
/*
int uses = 0;

int use_machine(vector<int> v){
	int count = 0;
	uses++;
	vector<int> shrooms = 
	for (int i = 1; i < v.size(); ++i){
		if (shrooms[v[i]] != shrooms[v[i - 1]]){
			count++;
		}
	}
	return count;
}
*/


int count_mushrooms(int n) {
	if (n < 220){
		int a = 1;
		for (int i = 1; i < n; ++i){
			a += 1 - use_machine({ 0, i });
		}
		return a;
	}
	int asize = 1;
	int bsize = 0;
	vector<int> a(1, 0);
	vector<int> b;
	if (use_machine({ 0, 1 }) == 1){
		b.push_back(1);
		bsize++;
	}
	else{
		a.push_back(1);
		asize++;
	}
	if (use_machine({ 0, 2 }) == 1){
		b.push_back(2);
		bsize++;
	}
	else{
		a.push_back(2);
		asize++;
	}
	for (int i = 3; i <= 200; i += 2){
		if (asize > bsize){
			int h = use_machine({ i, a[0], i + 1, a[1]});
			//cout << i << " " << a[0] << " " << i + 1 << " " << a[1] << " :: " << h << " :: a" << endl;
			if (h == 0){
				asize += 2;
				a.push_back(i);
				a.push_back(i + 1);
			}
			else if (h == 3){
				bsize += 2;
				b.push_back(i);
				b.push_back(i + 1);
			}
			else{
				bsize += 1;
				asize += 1;
				if (h == 1){
					b.push_back(i);
					a.push_back(i + 1);
				}
				else{
					a.push_back(i);
					b.push_back(i + 1);
				}
			}
		}

		else {
			int h = use_machine({ i, b[0], i + 1, b[1] });
			//cout << i << " " << b[0] << " " << i + 1 << " " << b[1] << " :: " << h << " :: b" << endl;
			if (h == 0){
				bsize += 2;
				b.push_back(i);
				b.push_back(i + 1);
			}
			else if (h == 3){
				asize += 2;
				a.push_back(i);
				a.push_back(i + 1);
			}
			else{
				bsize += 1;
				asize += 1;
				if (h == 1){
					a.push_back(i);
					b.push_back(i + 1);
				}
				else{
					b.push_back(i);
					a.push_back(i + 1);
				}
			}
		}

		
	}
	/*
	for (auto u : a){
		cout << u << " ";
	}
	cout << endl << endl;
	for (auto u : b){
		cout << u << " ";
	}
	*/
	
	int i = 201;
	int tally = asize;
	while (true){
		if (a.size() < b.size()){
			vector<int> p;
			int w = i;
			for (int j = 0; j < bsize; ++j){
				p.push_back(i);
				p.push_back(b[j]);
				i++;
				if (i == n){
					break;
				}
			}
			int h = use_machine(p);
			if (h % 2 == 0){
				b.push_back(w);
				tally += h / 2;
				bsize++;

			}
			else{
				a.push_back(w);
				tally++;
				asize++;
				tally += (h - 1) / 2;
			}
			if (i == n){
				return tally;
			}
		}
		else{
			vector<int> p;
			int w = i;
			int psize = 0;
			for (int j = 0; j < asize; ++j){
				p.push_back(i);
				p.push_back(a[j]);
				psize++;
				i++;
				if (i == n){
					break;
				}
			}
			int h = use_machine(p);
			if (h % 2 == 0){
				a.push_back(w);
				asize++;
				tally++;
				tally += (psize - 1) - (h / 2);

			}
			else{
				b.push_back(w);
				bsize++;
				tally += (psize - 1) - ((h - 1) / 2);
			}
			if (i == n){
				return tally;
			}
		}
		if (i == n){
			return tally;
		}
	}
}
/*
int main(){
	int g = count_mushrooms(19002);
	cout << endl << endl << g << endl << uses;
	return 0;
}
*/

• Subtask 1: 91.8699 / 100