#include "transfer.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> get_attachment(vector<int> source) {
int n = source.size(), b;
if(n == 63)b = 6;
else b = 8;
vector<int> v;
for(int i = 0; i < b; i++)v.push_back(0);
int tot = 0;
for(int i = 1; i <= n; i++){
for(int j = 0; j < b; j++)
if(i & (1<<j))v[j] ^= source[i-1];
tot ^= source[i-1];
}
v.push_back(tot);
return v;
}
vector<int> retrieve(vector<int> data) {
int n,b;
if(data.size() >= 255){ n = 255; b = 8; }
else{ n = 63; b= 6; }
vector<int> og, x;
for(int i = 0; i < b; i++)x.push_back(0);
int tot = 0;
for(int i = 1; i <= n; i++){
for(int j = 0; j < b; j++)
if(i & (1<<j))x[j] ^= data[i-1];
tot ^= data[i-1];
og.push_back(data[i-1]);
}
int id = 0, l = 0, qtd = 0;
for(int i = 0; i < b; i++){
if(x[i] != data[n+i]){
id += (1<<i);
l = i;
qtd++;
}
}
if(id != 0)
if(qtd > 1 || tot != data.back())og[id-1] ^= 1;
return og;
}
