Submission #217341

#	Time	Username	Problem	Language	Result	Execution time	Memory
217341		Sorting	Xoractive (IZhO19_xoractive)	C++14	100 / 100	7 ms	512 KiB

Xoractive

#include <bits/stdc++.h>
#include "interactive.h"

using namespace std;

const int kBits = 7;

map<int, bool> mp[kBits];

vector<int> guess(int n) {
	vector <int> ans(n);
	ans[0] = ask(1);

	for(int i = 0; i < 7; ++i){
		vector<int> v;
		for(int j = 2; j <= n; ++j){
			if((1 << i) & j)
				v.push_back(j);
		}

		if(v.empty())
			continue;

		vector<int> pairs_without = get_pairwise_xor(v);
		pairs_without.insert(pairs_without.begin(), 0);
		v.push_back(1);
		vector<int> pairs_with = get_pairwise_xor(v);

		for(int idx_with = 0, idx_without = 0; idx_with < pairs_with.size(); ++idx_with){
			if(idx_without < pairs_without.size() && pairs_with[idx_with] == pairs_without[idx_without])
				++idx_without;
			else
				mp[i][pairs_with[idx_with]] = true;
		}
	}

	for(int i = 2; i <= n; ++i){
		int first_bit = 0;
		for(; first_bit < kBits; ++first_bit)
			if((1 << first_bit) & i)
				break;

		ans[i - 1] = -1;
		for(auto p: mp[first_bit]){
			int x = p.first;
			bool ok = true;

			for(int bit = 0; bit < kBits; ++bit){
				if(bit == first_bit)
					continue;

				if((1 << bit) & i){
					if(!mp[bit].count(x)){
						ok = false;
						break;
					}
				}
				else{
					if(mp[bit].count(x)){
						ok = false;
						break;
					}
				}
			}

			if(ok){
				ans[i - 1] = x ^ ans[0];
				break;
			}
		}
	}

	return ans;
}

Compilation message (stderr)

Xoractive.cpp: In function 'std::vector<int> guess(int)':
Xoractive.cpp:29:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int idx_with = 0, idx_without = 0; idx_with < pairs_with.size(); ++idx_with){
                                          ~~~~~~~~~^~~~~~~~~~~~~~~~~~~
Xoractive.cpp:30:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(idx_without < pairs_without.size() && pairs_with[idx_with] == pairs_without[idx_without])
       ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 94 / 94