Submission #743489

#	Time	Username	Problem	Language	Result	Execution time	Memory
743489		boris_mihov	Unscrambling a Messy Bug (IOI16_messy)	C++17	100 / 100	2 ms	468 KiB

messy

#include "messy.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <bitset>
#include <random>

typedef long long llong;
const int MAXN = 256;
const int MAXLOG = 8;
const int INF  = 1e9;

std::vector <int> perm;
std::vector <int> restore_permutation(int n, int w, int r) 
{
    perm.resize(n, 0);
    std::string element(n, '0');
    for (int bit = 0 ; (1 << bit) < n ; ++bit)
    {
        for (int i = 0 ; i < n ; ++i)
        {
            if (i & (1 << bit))
            {
                if (element[i] == '0') element[i] = '1';
                else element[i] = '0';
                add_element(element);
                if (element[i] == '0') element[i] = '1';
                else element[i] = '0';
            }
        }

        for (int i = 0 ; i < n && bit > 0 ; ++i)
        {
            if (i & (1 << bit - 1))
            {
                element[i] = '0';
            }
        }

        for (int i = 0 ; i < n ; ++i)
        {
            if (i & (1 << bit))
            {
                element[i] = '1';
            }
        }
    }

    compile_set();
    std::vector <int> last;
    std::fill(element.begin(), element.end(), '0');
    for (int bit = 0 ; (1 << bit) < n ; ++bit)
    {
        std::vector <int> curr;
        for (int i = 0 ; i < n ; ++i)
        {
            if (element[i] == '0') element[i] = '1';
            else element[i] = '0';

            if (check_element(element))
            {
                perm[i] |= (1 << bit);
                curr.push_back(i);
            }

            if (element[i] == '0') element[i] = '1';
            else element[i] = '0';
        }

        for (const int &i : last)
        {
            element[i] = '0';
        }

        for (const int &i : curr)
        {
            element[i] = '1';
        }

        last = curr;
    }

    return perm;
}

Compilation message (stderr)

messy.cpp: In function 'std::vector<int> restore_permutation(int, int, int)':
messy.cpp:36:31: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   36 |             if (i & (1 << bit - 1))
      |                           ~~~~^~~

• Subtask 1: 20 / 20
• Subtask 2: 18 / 18
• Subtask 3: 11 / 11
• Subtask 4: 21 / 21
• Subtask 5: 30 / 30