Submission #668264

#	Time	Username	Problem	Language	Result	Execution time	Memory
668264		finn__	Unscrambling a Messy Bug (IOI16_messy)	C++17	100 / 100	2 ms	468 KiB

messy

#include <bits/stdc++.h>
#include "messy.h"
using namespace std;

void insert_all(int n, int j, string mask)
{
    if (n == 1)
        return;

    string mask1(mask.begin(), mask.end()), mask2(mask.begin(), mask.end());

    for (int i = j; i < j + n / 2; i++)
    {
        string s(mask.begin(), mask.end());
        s[i] = '1';
        add_element(s);
        mask2[i] = '1';
    }

    for (int i = j + n / 2; i < j + n; i++)
        mask1[i] = '1';

    insert_all(n / 2, j, mask1);
    insert_all(n / 2, j + n / 2, mask2);
}

void retrieve_permutation(int n, int j, string mask, vector<int> &p)
{
    if (n == 1)
    {
        for (int i = 0; i < mask.size(); i++)
            if (mask[i] == '0')
            {
                p[i] = j;
                return;
            }
    }

    string mask1(mask.begin(), mask.end()), mask2(mask.begin(), mask.end());

    for (int i = 0; i < mask.size(); i++)
    {
        if (mask[i] == '0')
        {
            string s(mask.begin(), mask.end());
            s[i] = '1';
            if (check_element(s))
                mask2[i] = '1';
            else
                mask1[i] = '1';
        }
    }

    retrieve_permutation(n / 2, j, mask1, p);
    retrieve_permutation(n / 2, j + n / 2, mask2, p);
}

std::vector<int> restore_permutation(int n, int w, int r)
{
    string mask;
    for (int i = 0; i < n; i++)
        mask.push_back('0');
    insert_all(n, 0, mask);
    compile_set();
    vector<int> p(n);
    retrieve_permutation(n, 0, mask, p);
    return p;
}

Compilation message (stderr)

messy.cpp: In function 'void retrieve_permutation(int, int, std::string, std::vector<int>&)':
messy.cpp:31:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         for (int i = 0; i < mask.size(); i++)
      |                         ~~^~~~~~~~~~~~~
messy.cpp:41:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     for (int i = 0; i < mask.size(); i++)
      |                     ~~^~~~~~~~~~~~~

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