Submission #957425

#	Time	Username	Problem	Language	Result	Execution time	Memory
957425		yellowtoad	Counting Mushrooms (IOI20_mushrooms)	C++17	99.56 / 100	7 ms	852 KiB

mushrooms

#include "mushrooms.h"
#include <iostream>
#include <vector>
#include <random>
#include <chrono>
#include <algorithm>
#define query use_machine
#define pb push_back
using namespace std;

int count_mushrooms(int n) {
	mt19937 rng(time(0));
		const int lim = 105;
		int pos, cnt, tmp;
		vector<int> a, b, v, q, ar, c, d;
		for (int i = 1; i < n; i++) ar.pb(i);
		for (int i = 1; i <= 10; i++) shuffle(ar.begin(),ar.end(),rng);
		ar.pb(0);
		reverse(ar.begin(),ar.end());
		if (n == 2) return 2-query({ar[0],ar[1]});
		a.pb(ar[0]);
		for (int i = 1; i <= 2; i++) {
			//if ((a.size() >= 2) || (b.size() >= 2)) break;
			pos = i+1;
			if (query({ar[0],ar[i]}) == 0) a.pb(ar[i]); 
			else b.pb(ar[i]);
		}
		while ((a.size() < lim) && (b.size() < lim)) {
			if ((pos+2 < n) && (a.size() >= 2) && (b.size() >= 2)) {
				tmp = query({a[0],ar[pos],a[1],b[0],ar[pos+1],b[1],ar[pos+2]});
				if (tmp%2 == 0) a.pb(ar[pos+2]);
				else b.pb(ar[pos+2]);
				if ((tmp-1)/2 == 0) a.pb(ar[pos]),b.pb(ar[pos+1]);
				else if ((tmp-1)/2 == 2) a.pb(ar[pos+1]),b.pb(ar[pos]);
				else {
					c.pb(ar[pos]); c.pb(ar[pos+1]);
					if (c.size() == 6) {
						tmp = query({a[0],c[0],c[1],a[1],b[0],c[2],c[3],b[1],c[4],c[5]});
						if (tmp%2 == 0) a.pb(c[4]), a.pb(c[5]);
						else b.pb(c[4]), b.pb(c[5]);
						if ((tmp-1)/2 == 0) a.pb(c[0]), a.pb(c[1]), b.pb(c[2]), b.pb(c[3]);
						else if ((tmp-1)/2 == 2) a.pb(c[2]), a.pb(c[3]), b.pb(c[0]), b.pb(c[1]);
						else {
							d.pb(c[0]); d.pb(c[1]); d.pb(c[2]); d.pb(c[3]);
							if (d.size() == 8) {
								tmp = query({a[0],d[0],d[1],d[2],d[3],a[1],d[4],d[5],d[6],d[7]});
								if (tmp == 0) a.pb(d[0]), a.pb(d[1]), a.pb(d[2]), a.pb(d[3]), a.pb(d[4]), a.pb(d[5]), a.pb(d[6]), a.pb(d[7]);
								else if (tmp == 1) a.pb(d[0]), a.pb(d[1]), a.pb(d[2]), a.pb(d[3]), b.pb(d[4]), b.pb(d[5]), b.pb(d[6]), b.pb(d[7]);
								else if (tmp == 2) b.pb(d[0]), b.pb(d[1]), b.pb(d[2]), b.pb(d[3]), a.pb(d[4]), a.pb(d[5]), a.pb(d[6]), a.pb(d[7]);
								else b.pb(d[0]), b.pb(d[1]), b.pb(d[2]), b.pb(d[3]), b.pb(d[4]), b.pb(d[5]), b.pb(d[6]), b.pb(d[7]);
								d.clear();
							}
						}
						c.clear();
					}
				}
				pos += 3;
			} else if (pos+1 < n) {
				if (a.size() >= 2) {
					tmp = query({a[0],ar[pos],a[1],ar[pos+1]});
					if (tmp == 0) a.pb(ar[pos]), a.pb(ar[pos+1]);
					else if (tmp == 1) a.pb(ar[pos]), b.pb(ar[pos+1]);
					else if (tmp == 2) b.pb(ar[pos]), a.pb(ar[pos+1]);
					else b.pb(ar[pos]), b.pb(ar[pos+1]);
				} else {
					tmp = query({b[0],ar[pos],b[1],ar[pos+1]});
					if (tmp == 0) b.pb(ar[pos]), b.pb(ar[pos+1]);
					else if (tmp == 1) b.pb(ar[pos]), a.pb(ar[pos+1]);
					else if (tmp == 2) a.pb(ar[pos]), b.pb(ar[pos+1]);
					else a.pb(ar[pos]), a.pb(ar[pos+1]);
				}
				pos += 2;
			} else break;
		}
		if (c.size() == 2) {
			tmp = query({a[0],c[0],a[1],c[1]});
			if (tmp == 0) a.pb(c[0]), a.pb(c[1]);
			else if (tmp == 1) a.pb(c[0]), b.pb(c[1]);
			else if (tmp == 2) b.pb(c[0]), a.pb(c[1]);
			else b.pb(c[0]), b.pb(c[1]);
		}
		if (c.size() == 4) {
			tmp = query({a[0],c[0],c[1],a[1],c[2],c[3]});
			if (tmp == 0) a.push_back(c[0]), a.push_back(c[1]), a.push_back(c[2]), a.push_back(c[3]);
			else if (tmp == 1) a.push_back(c[0]), a.push_back(c[1]), b.push_back(c[2]), b.push_back(c[3]);
			else if (tmp == 2) b.push_back(c[0]), b.push_back(c[1]), a.push_back(c[2]), a.push_back(c[3]);
			else b.push_back(c[0]), b.push_back(c[1]), b.push_back(c[2]), b.push_back(c[3]);
		}
		if (d.size()) {
			tmp = query({a[0],d[0],d[1],d[2],d[3]});
			if (tmp == 0) a.pb(d[0]), a.pb(d[1]), a.pb(d[2]), a.pb(d[3]);
			else b.pb(d[0]), b.pb(d[1]), b.pb(d[2]), b.pb(d[3]);
		}
		cnt = a.size();
		for (pos; pos < n; pos++) {
			v.pb(ar[pos]);
			if (v.size() == max(a.size(),b.size())) {
				if (a.size() >= b.size()) {
					q.clear();
					for (int i = 0; i < v.size(); i++) {
						q.pb(a[i]);
						q.pb(v[i]);
					}
					tmp = query(q);
					cnt += a.size()-(tmp+1)/2;
					if (tmp%2) b.pb(ar[pos]);
					else a.pb(ar[pos]);
				} else {
					q.clear();
					for (int i = 0; i < v.size(); i++) {
						q.pb(b[i]);
						q.pb(v[i]);
					}
					tmp = query(q);
					cnt += (tmp+1)/2;
					if (tmp%2) a.pb(ar[pos]);
					else b.pb(ar[pos]);
				}
				v.clear();
			}
		}
		if (v.size()) {
			if (a.size() >= b.size()) {
				q.clear();
				for (int i = 0; i < v.size(); i++) {
					q.pb(a[i]);
					q.pb(v[i]);
				}
				tmp = query(q);
				cnt += v.size()-(tmp+1)/2;
				if (tmp%2) b.pb(ar[pos]);
				else a.pb(ar[pos]);
			} else {
				q.clear();
				for (int i = 0; i < v.size(); i++) {
					q.pb(b[i]);
					q.pb(v[i]);
				}
				tmp = query(q);
				cnt += (tmp+1)/2;
				if (tmp%2) a.pb(ar[pos]);
				else b.pb(ar[pos]);
			}
		}
		return cnt;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int count_mushrooms(int)':
mushrooms.cpp:95:8: warning: statement has no effect [-Wunused-value]
   95 |   for (pos; pos < n; pos++) {
      |        ^~~
mushrooms.cpp:100:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |      for (int i = 0; i < v.size(); i++) {
      |                      ~~^~~~~~~~~~
mushrooms.cpp:110:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |      for (int i = 0; i < v.size(); i++) {
      |                      ~~^~~~~~~~~~
mushrooms.cpp:125:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |     for (int i = 0; i < v.size(); i++) {
      |                     ~~^~~~~~~~~~
mushrooms.cpp:135:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  135 |     for (int i = 0; i < v.size(); i++) {
      |                     ~~^~~~~~~~~~

• Subtask 1: 99.5595 / 100