Submission #143762

#	Time	Username	Problem	Language	Result	Execution time	Memory
143762		mahmoudbadawy	Data Transfer (IOI19_transfer)	C++17	100 / 100	75 ms	2752 KiB

transfer

#include "transfer.h"
using namespace std;

std::vector<int> get_attachment(std::vector<int> source) {
	int x=0;
	vector<int> v;
	for(int i=0;i<source.size();i++)
	{
		if(source[i]==1) x^=(i+1);
	}
	int sz=(source.size()==63?6:8),xr=0;
	while(sz--)
	{
		v.push_back(x%2); xr^=x%2; x/=2;
	}
	v.push_back(xr);
	return v;
}

std::vector<int> retrieve(std::vector<int> data) {
	int org=data.size()==7+63?63:255;
	int xr=0;
	for(int i=org;i<data.size();i++) xr^=data[i];
	if(xr) return vector<int>(data.begin(),data.begin()+org);
	for(int i=data.size()-2;i>=org;i--)
	{
		xr*=2; xr+=data[i];
	}
	int x=0;
	for(int i=0;i<org;i++)
		if(data[i]) x^=(i+1);
	if(x!=xr) data[(x^xr)-1]^=1;
	return vector<int>(data.begin(),data.begin()+org);
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:7:15: 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:23:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=org;i<data.size();i++) xr^=data[i];
                ~^~~~~~~~~~~~

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