Submission #247445

#	Time	Username	Problem	Language	Result	Execution time	Memory
247445		stoyan_malinin	Data Transfer (IOI19_transfer)	C++14	100 / 100	93 ms	2776 KiB

transfer

#include "transfer.h"
//#include "grader.cpp"

#include<iostream>
#include<vector>

using namespace std;

int BITCnt;

vector<int> get_attachment(vector<int> source)
{
    if(source.size()==63) BITCnt = 6;
    else BITCnt = 8;

    int val1 = 0, val2 = 0;
    for(int i = 0;i<source.size();i++)
    {
        if(source[i]==1)
        {
            val1 ^= 1;
            val2 ^= i + 1;
        }
    }

    vector <int> out;
    for(int bit = 0;bit<BITCnt;bit++) out.push_back(((val2>>bit)&1));
    out.push_back(val1);

    return out;
}

vector<int> retrieve(vector<int> data)
{
    if(data.size()==70) BITCnt = 6;
    else BITCnt = 8;

    vector <int> info;
    int val1 = 0, val2 = 0;
    int expectedVal1 = 0, expectedVal2 = 0;

    info = vector <int>(data.begin(), data.begin()+(data.size()-(BITCnt+1)));
    for(int i = 0;i<info.size();i++)
    {
        if(info[i]==1)
        {
            val1 ^= 1;
            val2 ^= i + 1;
        }
    }

    for(int i = (data.size()-(BITCnt+1));i<data.size()-1;i++) expectedVal2 += (data[i]<<(i-(data.size()-(BITCnt+1))));
    expectedVal1 = data.back();

    if(val1==expectedVal1 || val2==expectedVal2) return info;
    for(int i = 0;i<info.size();i++)
    {
        if((val2^(i+1))==expectedVal2)
        {
            info[i] ^= 1;
            return info;
        }
    }
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:17:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<source.size();i++)
                   ~^~~~~~~~~~~~~~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:43:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<info.size();i++)
                   ~^~~~~~~~~~~~
transfer.cpp:52:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = (data.size()-(BITCnt+1));i<data.size()-1;i++) expectedVal2 += (data[i]<<(i-(data.size()-(BITCnt+1))));
                                          ~^~~~~~~~~~~~~~
transfer.cpp:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0;i<info.size();i++)
                   ~^~~~~~~~~~~~
transfer.cpp:64:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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