Submission #802852

#	Time	Username	Problem	Language	Result	Execution time	Memory
802852		happypotato	Scales (IOI15_scales)	C++17	71.43 / 100	227 ms	432 KiB

scales

#include "scales.h"

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back

void init(int T) {
	
}

/*
getHeaviest()
getLightest()
getMedian()
getNextLightest()
*/

vector<pair<int, vector<int>>> clues; // {type, {answer, [query elements]}}
vector<int> perm = {0, 1, 2, 3, 4, 5, 6};
vector<vector<int>> FindAllPossible() {
	// cerr << "CURRENT CLUES:\n";
	// for (pair<int, vector<int>> &cur : clues) {
	// 	cerr << cur.ff << " | ";
	// 	for (int &x : cur.ss) cerr << x << ' ';
	// 	cerr << endl;
	// }
	sort(perm.begin(), perm.end());
	vector<vector<int>> res = {};
	do {
		bool valid = true;
		for (pair<int, vector<int>> &cur : clues) {
			// cerr << "CLUE " << cur.ff << ' ';
			// for (int &x : cur.ss) cerr << x << ' '; cerr << endl;
			if (cur.ff == 1) {
				for (int i = 1; i <= 3; i++) {
					if (cur.ss[0] == cur.ss[i]) continue;
					valid &= (perm[cur.ss[0]] > perm[cur.ss[i]]);
				}
			}
			if (cur.ff == 2) {
				for (int i = 1; i <= 3; i++) {
					if (cur.ss[0] == cur.ss[i]) continue;
					valid &= (perm[cur.ss[0]] < perm[cur.ss[i]]);
				}
			}
			if (cur.ff == 3) {
				int cnt = 0;
				for (int i = 1; i <= 3; i++) {
					if (cur.ss[0] == cur.ss[i]) continue;
					cnt += (perm[cur.ss[0]] < perm[cur.ss[i]]);
				}
				valid &= (cnt == 1);
			}
			if (cur.ff == 4) {
				bool allsmaller = true;
				for (int i = 1; i <= 3; i++) {
					allsmaller &= (perm[cur.ss[i]] < perm[cur.ss[4]]);
				}
				if (allsmaller) {
					for (int i = 1; i <= 3; i++) {
						if (cur.ss[0] == cur.ss[i]) continue;
						valid &= (perm[cur.ss[i]] > perm[cur.ss[0]]);
					}
				} else {
					valid &= (perm[cur.ss[0]] > perm[cur.ss[4]]);
					for (int i = 1; i <= 3; i++) {
						if (cur.ss[0] == cur.ss[i]) continue;
						valid &= (perm[cur.ss[i]] < perm[cur.ss[4]] || perm[cur.ss[i]] > perm[cur.ss[0]]);
					}
				}
			}
			if (!valid) break;
		}
		if (valid) {
			// cerr << "FOUND ";
			// for (int &x : perm) cerr << x << ' ';
			// cerr << endl;
			res.pb(perm);
		}
	} while (next_permutation(perm.begin() + 1, perm.end()));
	return res;
}
void Answer(vector<int> v) {
	int ans[6];
	for (int i = 1; i <= 6; i++) ans[v[i] - 1] = i;
	answer(ans);
}

int Heaviest(int a, int b, int c = 0) {
	if (c == 0) c = (min(a, b) != 1 ? 1 : max(a, b) != 2 ? 2 : 3);
	int res = getHeaviest(a, b, c);
	clues.pb({1, {res, a, b, c}});
	return res;
}
int Lightest(int a, int b, int c = 0) {
	if (c == 0) c = (min(a, b) != 1 ? 1 : max(a, b) != 2 ? 2 : 3);
	int res = getLightest(a, b, c);
	clues.pb({2, {res, a, b, c}});
	return res;
}
int Median(int a, int b, int c) {
	int res = getMedian(a, b, c);
	clues.pb({3, {res, a, b, c}});
	return res;
}
int NextLightest(int a, int b, int c, int d) {
	int res = getNextLightest(a, b, c, d);
	clues.pb({4, {res, a, b, c, d}});
	return res;
}
/*
getHeaviest()
getLightest()
getMedian()
getNextLightest()
*/
int TryHeaviest(int a, int b, int c) {
	int res = 0;
	clues.pb({1, {a, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({1, {b, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({1, {c, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	return res;
}
int TryLightest(int a, int b, int c) {
	int res = 0;
	clues.pb({2, {a, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({2, {b, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({2, {c, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	return res;
}
int TryMedian(int a, int b, int c) {
	int res = 0;
	clues.pb({3, {a, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({3, {b, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({3, {c, a, b, c}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	return res;
}
int TryNextLightest(int a, int b, int c, int d) {
	int res = 0;
	clues.pb({4, {a, a, b, c, d}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({4, {b, a, b, c, d}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	clues.pb({4, {c, a, b, c, d}}); res = max(res, (int)FindAllPossible().size()); clues.pop_back();
	return res;
}

mt19937 rng(time(NULL));
int GetRand(int x) {
	return rng() % x;
}

void orderCoins() {
	clues.clear();

	int temp = Lightest(1, 2, 3);
	if (temp == 1) Heaviest(2, 3, 4);
	if (temp == 2) Heaviest(1, 3, 4);
	if (temp == 3) Heaviest(1, 2, 4);
	// cout << FindAllPossible().size() << endl;

	// try pure exhaust?
	vector<vector<int>> fin = FindAllPossible();
	while (fin.size() > 1) {
		// cerr << "Current size: " << fin.size() << ", ";
		// cerr << "Current queries: " << clues.size() << endl;
		int cursz = fin.size(), res;
		vector<int> nxtquery;
		vector<vector<int>> nxtqueries;
		for (int a = 1; a <= 6; a++) {
			for (int b = a + 1; b <= 6; b++) {
				for (int c = b + 1; c <= 6; c++) {
					res = TryHeaviest(a, b, c);
					if (res <= cursz) {
						if (res < cursz) nxtqueries.clear();
						nxtqueries.pb({1, a, b, c});
						cursz = res;
					}

					res = TryLightest(a, b, c);
					if (res <= cursz) {
						if (res < cursz) nxtqueries.clear();
						nxtqueries.pb({2, a, b, c});
						cursz = res;
					}

					res = TryMedian(a, b, c);
					if (res <= cursz) {
						if (res < cursz) nxtqueries.clear();
						nxtqueries.pb({3, a, b, c});
						cursz = res;
					}

					for (int d = 1; d <= 6; d++) {
						if (d == a || d == b || d == c) continue;
						res = TryNextLightest(a, b, c, d);
						if (res <= cursz) {
							if (res < cursz) nxtqueries.clear();
							nxtqueries.pb({4, a, b, c, d});
							cursz = res;
						}
					}
				}
			}
		}
		nxtquery = nxtqueries[(GetRand(nxtqueries.size()))];
		if (nxtquery.front() == 1) Heaviest(nxtquery[1], nxtquery[2], nxtquery[3]);
		if (nxtquery.front() == 2) Lightest(nxtquery[1], nxtquery[2], nxtquery[3]);
		if (nxtquery.front() == 3) Median(nxtquery[1], nxtquery[2], nxtquery[3]);
		if (nxtquery.front() == 4) NextLightest(nxtquery[1], nxtquery[2], nxtquery[3], nxtquery[4]);
		fin = FindAllPossible();
	}
	Answer(fin.front());
}
/*
15 edges to consider (know all -> must can sort)
full sol: 6 queries (by math)
(current sol: 7 queries)

full sol is consider 2 queries at once (?)
*/

Compilation message (stderr)

scales.cpp: In function 'void init(int)':
scales.cpp:10:15: warning: unused parameter 'T' [-Wunused-parameter]
   10 | void init(int T) {
      |           ~~~~^
scales.cpp: In function 'int GetRand(int)':
scales.cpp:151:15: warning: conversion from 'std::mersenne_twister_engine<long unsigned int, 32, 624, 397, 31, 2567483615, 11, 4294967295, 7, 2636928640, 15, 4022730752, 18, 1812433253>::result_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  151 |  return rng() % x;
      |         ~~~~~~^~~
scales.cpp: In function 'void orderCoins()':
scales.cpp:168:23: warning: conversion from 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  168 |   int cursz = fin.size(), res;
      |               ~~~~~~~~^~
scales.cpp:207:49: warning: conversion from 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  207 |   nxtquery = nxtqueries[(GetRand(nxtqueries.size()))];
      |                                  ~~~~~~~~~~~~~~~^~

• Subtask 1: 71.428571 / 100