#include "transfer.h"
#include <vector>
using namespace std;
typedef vector<int> vi;
vi get_attachment(vi aa) {
int n = aa.size(), l = 0;
while (1 << l <= n)
l++;
vi xx(l + 1, 0);
int x = 0;
for (int i = 0; i < n; i++)
if (aa[i] == 1)
x ^= i + 1;
int k = 0;
for (int h = 0; h < l; h++)
if ((x & 1 << h) != 0)
xx[h] = 1, k++;
if (k % 2 != 0)
xx[l] = 1;
return xx;
}
vi retrieve(vi bb) {
int m = bb.size(), n = 0, l = 0;
while (1) {
n++;
while (1 << l <= n)
l++;
if (m == n + l + 1)
break;
}
int x = 0, k = 0;
for (int h = 0; h <= l; h++)
if (bb[n + h] == 1) {
if (h < l)
x |= 1 << h;
k++;
}
bb.resize(n);
if (k % 2 == 0) {
for (int i = 0; i < n; i++)
if (bb[i] == 1)
x ^= i + 1;
if (x != 0)
bb[x - 1] ^= 1;
}
return bb;
}
