Submission #573166

#	Time	Username	Problem	Language	Result	Execution time	Memory
573166		Jomnoi	Data Transfer (IOI19_transfer)	C++17	100 / 100	79 ms	2500 KiB

transfer

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

vector <int> get_attachment(vector <int> source) {
	int X = 0, cnt1 = 0, sz = log2(source.size() + 1);
	for(int i = 0; i < source.size(); i++) {
		if(source[i] == 1) {
			X ^= (i + 1);
		}
	}

	vector <int> K;
	while(X > 0 or K.size() < sz) {
		K.push_back(X % 2);
		cnt1 += X % 2;
		X /= 2;
	}
	K.push_back(cnt1 % 2);

	return K;
}

vector <int> retrieve(vector <int> data) {
	int cnt1 = data.back(), sz = log2(data.size()), X = 0;
	data.pop_back();

	while(sz--) {
		X *= 2;
		X += data.back();
		cnt1 += data.back();
		data.pop_back();
	}

	if(cnt1 % 2 == 1) {
		return data;
	}

	for(int i = 0; i < data.size(); i++) {
		if(data[i] == 1) {
			X ^= (i + 1);
		}
	}

	if(X != 0) {
		data[X - 1] ^= 1;
	}
	return data;
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:7:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |  for(int i = 0; i < source.size(); i++) {
      |                 ~~^~~~~~~~~~~~~~~
transfer.cpp:14:26: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   14 |  while(X > 0 or K.size() < sz) {
      |                 ~~~~~~~~~^~~~
transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:39:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |  for(int i = 0; i < data.size(); i++) {
      |                 ~~^~~~~~~~~~~~~

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