Submission #941627

#	Time	Username	Problem	Language	Result	Execution time	Memory
941627		benjaminkleyn	Data Transfer (IOI19_transfer)	C++17	100 / 100	148 ms	2544 KiB

transfer

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

vector<int> get_attachment(vector<int> source) 
{
    int K = (source.size() < 100 ? 7 : 9);
    vector<int> attachment;
    int x = 0;
    for (int i = 0; i < source.size(); i++)
        x ^= source[i];
    source.push_back(x);
    attachment.push_back(x);
    for (int k = 0; k < K - 1; k++)
    {
        x = 0;
        for (int i = 0; i < source.size(); i++)
            if (i & (1 << k))
                x ^= source[i];
        attachment.push_back(x);
    }
    return attachment;
}

vector<int> retrieve(vector<int> data) 
{
    int K = (data.size() < 100 ? 7 : 9);
    vector<int> attachment(data.end() - (K - 1), data.end());
	data = vector<int>(data.begin(), data.end() - (K - 1));
    int x = 0;
    for (int i = 0; i < data.size(); i++) 
        x ^= data[i];
    if (x == 0)
    {
        data.pop_back();
        return data;
    }
    int result = 0;
    for (int k = 0; k < K - 1; k++)
    {
        x = attachment[k];
        for (int i = 0; i < data.size(); i++)
            if (i & (1 << k))
                x ^= data[i];
        if (x)
            result ^= (1 << k);
    }
    data[result] ^= 1;
    data.pop_back();
    return data;
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for (int i = 0; i < source.size(); i++)
      |                     ~~^~~~~~~~~~~~~~~
transfer.cpp:17:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |         for (int i = 0; i < source.size(); i++)
      |                         ~~^~~~~~~~~~~~~~~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for (int i = 0; i < data.size(); i++)
      |                     ~~^~~~~~~~~~~~~
transfer.cpp:42:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i = 0; i < data.size(); i++)
      |                         ~~^~~~~~~~~~~~~

• Subtask 1: 60 / 60
• Subtask 2: 40 / 40