C++ count_bits函数代码示例

uint64_t sieve_count(uint64_t* s, uint64_t prime_num, uint64_t first, uint64_t last, uint64_t L, uint64_t U, uint64_t* s2)
{
  /*use Legendre sieve for 2, 3, and 5 so sieve s does not have to store numbers
   divisible by 2, 3, or 5*/
  if      (prime_num == 1) return last - (first -1);
  else if (prime_num == 2) return last - last/2 - (first - 1 - (first -1)/2);
  else if (prime_num == 3) return last - last/2 - last/3 + last/6 -((first - 1) - (first - 1)/2 - (first - 1)/3 + (first - 1)/6);
  
  uint64_t a, b, c, ans;
  if(first > 0) a = (first  + NEXT[first % MOD])/MOD * GROUPS + POS[first % MOD];
  else a = 0;
  if (last > 0) b = (last   + PREV[last  % MOD])/MOD * GROUPS + POS[last % MOD];
  else b = 0;

  if (L > 1) c = (L-1 + PREV[(L-1) % MOD])/MOD * GROUPS + POS[(L-1) % MOD];
  else c = 0;


  if(a - c > 0 && b - c > 0) ans =  count_bits(s2, a - c, b - c);
  else ans = 0;  

  //  printf("L = %lu is bit %lu U is %lu\n", L, c, U);
  //  printf("sieve count args: prime_num = %lu first = %lu last = %lu L = %lu, U = %lu\n",prime_num,first,last,L,U);
  //printf("a = %lu b = %lu c = %lu\n",a,b,c);
  //  printf("start bit = %lu finish_bit = %lu\n", a-c, b-c);
  printf("L = %lu\ti = %lu\twheel = %lu\ttraditional = %lu\n",L, prime_num, ans, count_bits(s, first - L, last - L));

  return count_bits(s, first - L, last - L);
}

/* convert a netmask string (eg 255.255.255.0 or ffff:ff::) in +src+ into
 * the length (24) in +dst+.  Return 0 if some sort of failure, or 1 on
 * success.
 */
int inet_ptom (int af, const char *src, unsigned int *dst)
{
    union inX_addr addr;

    if (!empty_str(src)) {
        if (inet_pton (af, src, &addr) < 0) {
            *dst = 0;
            return 0;
        }
    }

    if (af == AF_INET) {
        *dst = count_bits(ntohl(addr.in4.s_addr));
        return 1;
    } else if (af == AF_INET6) {
        int i, count;
        for (i = 0, *dst = 0; i < 4; i++) {
            count = count_bits(htonl(addr.in6.s6_addr32[i]));
            *dst += count;
            if (count != 32) break;  /* Don't go any further if the mask has finished */
        }
        return 1;
    } else {
        *dst = 0;
        return 0;
    }
}

size_t BitMap::count() const{
    size_t cnt = 0;
    for(auto i = array.rbegin() ; i != array.rend() ; ++i){
        if (i == array.rbegin() && bitset_size % block_size){
            cnt += count_bits(*i & ((1u << bitset_size % block_size) - 1));
        } else {
            cnt += count_bits(*i);
        }
    }
    return cnt;
}

bool LoRaPHYUS915Hybrid::validate_channel_mask(uint16_t* channel_masks)
{
    bool mask_state = false;

    uint16_t block1 = 0;
    uint16_t block2 = 0;
    uint8_t index = 0;
    uint16_t temp_channel_masks[US915_HYBRID_CHANNEL_MASK_SIZE];

    // Copy channels mask to not change the input
    for (uint8_t i = 0; i < 4; i++) {
        temp_channel_masks[i] = channel_masks[i];
    }

    for(uint8_t i = 0; i < 4; i++) {
        block1 = temp_channel_masks[i] & 0x00FF;
        block2 = temp_channel_masks[i] & 0xFF00;

        if (count_bits(block1, 16) > 1) {

            temp_channel_masks[i] &= block1;
            temp_channel_masks[4] = 1 << ( i * 2 );
            mask_state = true;
            index = i;
            break;

        } else if( count_bits( block2, 16 ) > 1 ) {

            temp_channel_masks[i] &= block2;
            temp_channel_masks[4] = 1 << ( i * 2 + 1 );
            mask_state = true;
            index = i;
            break;

        }
    }

    // Do change the channel mask, if we have found a valid block.
    if (mask_state == true) {
        // Copy channels mask back again
        for (uint8_t i = 0; i < 4; i++) {
            channel_masks[i] = temp_channel_masks[i];

            if (i != index) {
                channel_masks[i] = 0;
            }
        }

        channel_masks[4] = temp_channel_masks[4];
    }

    return mask_state;
}

TEST(BitMatrixTest, SetReset)
{
  ocgl::BitMatrix m(4, 5);

  for (int i = 0; i < m.rows(); ++i)
    for (int j = 0; j < m.cols(); ++j) {
      EXPECT_EQ(0, count_bits(m));
      m.set(i, j);
      EXPECT_EQ(1, count_bits(m));
      m.reset(i, j);
      EXPECT_EQ(0, count_bits(m));
    }
}

int Scm_BitsCount0(const ScmBits *bits, int start, int end)
{
    int sw = start  / SCM_WORD_BITS;
    int ew = (end-1)/ SCM_WORD_BITS;
    int sb = start  % SCM_WORD_BITS;
    int eb = end    % SCM_WORD_BITS;

    if (start == end) return 0;
    if (sw == ew) return count_bits(~bits[sw] & SCM_BITS_MASK(sb, eb));

    u_long num = count_bits(~bits[sw] & SCM_BITS_MASK(sb, 0));
    for (sw++; sw < ew; sw++) num += count_bits(~bits[sw]);
    return num + (count_bits(~bits[ew] & SCM_BITS_MASK(0, eb)));
}

int main()
{
  std::cout << count_bits(8) << std::endl;
  std::cout << count_bits(15) << std::endl;
  std::cout << count_bits(10) << std::endl;
  std::cout << count_bits(100) << std::endl;
  std::cout << count_bits(127) << std::endl;

  std::cout << std::bitset<4 * 8>(182927) << std::endl;
  std::cout << std::bitset<4 * 8>(reverse(182927)) << std::endl;

  int a = 23;
  int b = 22;
  std::cout << a << " + " << b << ": " << add(a, b) << std::endl;
}

bool OMXPlayerVideo::Decode(OMXPacket *pkt)
{
  if(!pkt)
    return false;

  // some packed bitstream AVI files set almost all pts values to DVD_NOPTS_VALUE, but have a scattering of real pts values.
  // the valid pts values match the dts values.
  // if a stream has had more than 4 valid pts values in the last 16, the use UNKNOWN, otherwise use dts
  m_history_valid_pts = (m_history_valid_pts << 1) | (pkt->pts != DVD_NOPTS_VALUE);
  double pts = pkt->pts;
  if(pkt->pts == DVD_NOPTS_VALUE && (m_iCurrentPts == DVD_NOPTS_VALUE || count_bits(m_history_valid_pts & 0xffff) < 4))
    pts = pkt->dts;

  if (pts != DVD_NOPTS_VALUE)
    pts += m_iVideoDelay;

  if(pts != DVD_NOPTS_VALUE)
    m_iCurrentPts = pts;

  while((int) m_decoder->GetFreeSpace() < pkt->size)
  {
    OMXClock::OMXSleep(10);
    if(m_flush_requested) return true;
  }

  CLog::Log(LOGINFO, "CDVDPlayerVideo::Decode dts:%.0f pts:%.0f cur:%.0f, size:%d", pkt->dts, pkt->pts, m_iCurrentPts, pkt->size);
  m_decoder->Decode(pkt->data, pkt->size, pts);
  return true;
}

/*
 ***************************************************************************
 * Determine if a stat header line has to be displayed.
 *
 * RETURNS:
 * TRUE if a header line has to be displayed.
 ***************************************************************************
*/
int check_line_hdr(void)
{
	int i, rc = FALSE;

	/* Get number of options entered on the command line */
	if (get_activity_nr(act, AO_SELECTED, COUNT_OUTPUTS) > 1)
		return TRUE;

	for (i = 0; i < NR_ACT; i++) {
		if (IS_SELECTED(act[i]->options)) {
			/* Special processing for activities using a bitmap */
			if (act[i]->bitmap) {
				if (count_bits(act[i]->bitmap->b_array,
					       BITMAP_SIZE(act[i]->bitmap->b_size)) > 1) {
					rc = TRUE;
				}
			}
			else if (act[i]->nr > 1) {
				rc = TRUE;
			}
			/* Stop now since we have only one selected activity */
			break;
		}
	}

	return rc;
}

void main()
{
    /* Write a case statement to select which hack it is 
     * */
    count_bits();
    return;
}

unsigned int get_random_number_from_candidate_list_and_remove_it(CandidateListType *list, unsigned int index)
{
    unsigned int randomIndex;   // index of the selected candidate in the list
    unsigned int count;         // number of remaining candidates in the list
    unsigned int candidate;     // selected candidate

    assert(NULL != list && index < (NROWS*NCOLS) && "get_random_number_from_candidate_list_and_remove_it(): Bad input");

    // 1. count how many remaining numbers we have (how many set bits)
    count = count_bits(list[index]);
    assert(count > 0 && "get_random_number_from_candidate_list_and_remove_it(): No candidate remaining");

    // 2. generate random index (will be 0 when count is 1)
    randomIndex = (unsigned int) arc4random() % count;

    // 3. get the corresponding candidate
    for (candidate = 0; candidate < NCOLS; ++candidate)
    {
        if (BIT_CHECK(list[index],candidate)) {
            if (0 == randomIndex) {
                break;
            }
            else {
                --randomIndex;
            }
        }
    }
    assert(0 <= candidate && candidate < NCOLS && 0 == randomIndex && "get_random_number_from_candidate_list_and_remove_it(): Bad index");

    // 4. remove it from the candidate list
    BIT_CLEAR(list[index],candidate);

    return (unsigned int)(candidate+1); // Indices start at 0 but values start at 1, need to increase
}

//done
void scan_operands (operands_t operands) {
  printf("scan_operands() for %s\n", lc3_get_format_name(operands));
  int operandCount = 0;
  int numOperands  = count_bits(operands);
  int errorCount   = numErrors;
  for (operand_t op = FMT_R1; op <= FMT_STR; op <<= 1) {
    //if the bits are set
    //printf(" ");
    if(op & operands){
      //create a token
      char* token = next_token();
      //get the operand of that token
      if(token != NULL){
      get_operand(op,token);
      
        //if errorocunt is not equal return
       if (errorCount != numErrors)
        return; // error, so skip processing remainder of line
      //inc operand count
      operandCount++;
      //if the count is less then the operands 
      if(operandCount < numOperands){
        //get comma or error
        get_comma_or_error();
      }
      //check errorcount again
      if (errorCount != numErrors)
      return; // error, so skip processing remainder of line

    }
  }
  }
}

static int
VBR_quantize_granule(lame_internal_flags * gfc, gr_info * cod_info, FLOAT8 * xr34, int gr, int ch)
{
    int     status;

    /* encode scalefacs */
    if (gfc->is_mpeg1)
        status = scale_bitcount(&cod_info->scalefac, cod_info);
    else
        status = scale_bitcount_lsf(gfc, &cod_info->scalefac, cod_info);

    if (status != 0) {
        return -1;
    }

    /* quantize xr34 */
    cod_info->part2_3_length = count_bits(gfc, cod_info->l3_enc, xr34, cod_info);
    if (cod_info->part2_3_length >= LARGE_BITS)
        return -2;
    cod_info->part2_3_length += cod_info->part2_length;


    if (gfc->use_best_huffman == 1) {
        best_huffman_divide(gfc, cod_info);
    }
    return 0;
}

/* get size as unsigned char string */
static unsigned long unsigned_size(void *a)
{
	unsigned long t;
	LTC_ARGCHK(a != NULL);
	t = count_bits(a);
	if (mpa_cmp_short((const mpanum)a, 0) == 0) return 0;
	return (t>>3) + ((t&7)?1:0);
}

void	create_food(ULONG f)
{
	ULONG	i;
	SLONG	temp_segment;
	UWORD	orig_x, x, y;
	UWORD	form;

	if (f < MAX_FOODS)
	{
		form = 0;
		while (!form)
			form = (UWORD) ((rand()&rand())&0xffff);
		foods[f].Form = form;
		foods[f].Size = count_bits(form);
		foods[f].Effect = choose_effect();
		foods[f].Colour = food_colours[foods[f].Effect];
		foods[f].Timer = 2000;

		temp_segment = get_a_segment();
		if (temp_segment == -1)
			return;
		if (assign_a_food_position(temp_segment,form))
		{
			put_a_segment(temp_segment);
			return;
		}
		orig_x = x = segs[temp_segment].X;
		y = segs[temp_segment].Y;
		put_a_segment(temp_segment);

		for (i=0; i<16; i++)
		{
			if (form & 1)
			{
				temp_segment = get_a_segment();
				if (temp_segment != -1)
				{
					foods[f].Size++;
					segs[temp_segment].Next = foods[f].Head;
					segs[temp_segment].Colour = foods[f].Colour;
					segs[temp_segment].X = x;
					segs[temp_segment].Y = y;
					foods[f].Head = temp_segment;
				}
				else
					return;
			}
			x += BLOB_SIZE;
			if (x - orig_x == BLOB_SIZE*4)
			{
				x = orig_x;
				y += BLOB_SIZE;
			}
			form >>= 1;
		}
	}