#include <stdint.h>
#include <stdlib.h>

static uint8_t lfsr(uint8_t v) {
  const uint8_t bit = v>>7;
  v <<= 1;
  v ^= (-bit) & 0xA6;
  return v;
}

void vec(size_t n, uint8_t* out, uint8_t const* in)
{
  for (size_t i = 0; i < n; ++i) {
    out[i] = lfsr(in[i]);
  }
}