Submission #645835

#	Time	Username	Problem	Language	Result	Execution time	Memory
645835		boris_mihov	Xoractive (IZhO19_xoractive)	C++17	100 / 100	4 ms	388 KiB

Xoractive

#include "interactive.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <vector>
#include <map>
#include <set>

typedef long long llong;
const int MAXN = 250 + 10;
const int INF  = 1e9;

std::map <int,int> map; 
std::vector <int> ans, res, res2, queried;
std::multiset <int> s;

std::vector <int> query(std::vector <int> returned, int sz)
{
    std::vector <int> curr;
    for (int i = sz ; i < returned.size() ; i += 2)
    {
        curr.push_back(returned[i]);
    }

    return curr;
}

std::vector <int> guess(int n)
{
    ans.resize(n);
    ans[n-1] = ask(n);
    for (int log = 0 ; (1 << log) <= n-1 ; ++log)
    {
        s.clear();
        queried.clear();
        for (int i = 1 ; i <= n-1 ; ++i)
        {
            if ((i & (1 << log)))
            {
                queried.push_back(i);
            }
        }

        queried.push_back(n);
        if (queried.size() == 1) continue;
        res = query(get_pairwise_xor(queried), queried.size());
        if (queried.size() == 2)
        {
            map[res[0] ^ ans[n-1]] |= (1 << log);
            continue;
        }

        queried.pop_back();
        res2 = query(get_pairwise_xor(queried), queried.size());
        for (const int &i : res) s.insert(i);
        for (const int &i : res2) s.erase(s.find(i));
        for (const int &i : s)
        {
            map[i ^ ans[n-1]] |= (1 << log);
        }
    }

    for (auto [key, value] : map)
    {
        ans[value - 1] = key;
    }
    
    return ans;
}   

Compilation message (stderr)

Xoractive.cpp: In function 'std::vector<int> query(std::vector<int>, int)':
Xoractive.cpp:20:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for (int i = sz ; i < returned.size() ; i += 2)
      |                       ~~^~~~~~~~~~~~~~~~~

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