Submission #829645

#	Time	Username	Problem	Language	Result	Execution time	Memory
829645		haxorman	Data Transfer (IOI19_transfer)	C++14	0 / 100	4 ms	2456 KiB

transfer

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

vector<int> get_attachment(vector<int> source) {
    int end = 0;
    vector<int> res;
    for (int j = 0; (1 << j) < source.size(); ++j) {
        int val = 0;
        for (int i = 0; i < source.size(); ++i) {
            if (i & (1 << j)) {
                val ^= source[i];
            }
        }
        res.push_back(val);
        end ^= val;
    }
    res.push_back(end);

    return res;
}

vector<int> retrieve(vector<int> data) {
    assert(data.size() == 70 || data.size() == 264);

    bool smol = (data.size() < 255);
    vector<int> source;
    for (int i = 0; i < data.size() - (smol ? 7 : 9); ++i) {
        source.push_back(data[i]);
    }
    assert(source.size() == 63 || source.size() == 255);
    
    int end = 0;
    vector<int> lst;
    for (int i = data.size() - (smol ? 7 : 9); i < data.size() - 1; ++i) {
        lst.push_back(data[i]);
        end ^= data[i];
    }

    if (end != data.back()) {
        return source;
    }
    
    int bad = 0;
    for (int j = 0; (1 << j) < source.size(); ++j) {
        int val = 0;
        for (int i = 0; i < source.size(); ++i) {
            if (i & (1 << j)) {
                val ^= source[i];
            }
        }

        if (val != lst[j]) {
            bad += (1 << j);
        }
    }

    source[bad] ^= 1;
    return source;
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:8:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     for (int j = 0; (1 << j) < source.size(); ++j) {
      |                     ~~~~~~~~~^~~~~~~~~~~~~~~
transfer.cpp:10:27: 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: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:28:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     for (int i = 0; i < data.size() - (smol ? 7 : 9); ++i) {
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transfer.cpp:35:50: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |     for (int i = data.size() - (smol ? 7 : 9); i < data.size() - 1; ++i) {
      |                                                ~~^~~~~~~~~~~~~~~~~
transfer.cpp:45:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |     for (int j = 0; (1 << j) < source.size(); ++j) {
      |                     ~~~~~~~~~^~~~~~~~~~~~~~~
transfer.cpp:47:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         for (int i = 0; i < source.size(); ++i) {
      |                         ~~^~~~~~~~~~~~~~~

• Subtask 1: 0 / 60
• Subtask 2: 0 / 40