static void bitmap_init(int start, int num, int nbits, int type)
{
  /* YOUR CODE */
  dprintf("...start bitmap initialization with start=%d, num=%d, nbits=%d\n",start, num, nbits);
  //create bitmap with size of arry of chars neccessary to support num bits
  char *bitmap;
  //get size of bit array in bytes
  //if type then bitmap sector, else inode sector
  int size = -1;
  if(type){
	 size = array_size(SECTOR_BITMAP_SIZE * CHARBITS);
  }else{
	 size = array_size(INODE_BITMAP_SIZE * CHARBITS);
  }
  //allocate the neccessary bytes for the num size bitmap
  bitmap = (char *)calloc(size, sizeof(char));

  //initialize all bits to 0 (clear all bits)
  for (int i = 0; i < num; i++)
  {
    clear_bit(bitmap,i);
  }

  //for nbits set the bit (bit = 1)
   for (int i = 0; i < nbits; i++)
  {
    set_bit(bitmap,i);
  }

  //set the bits of the sector that thec current bitmap occupies
  for(int i = start; i < start + num; i++) set_bit(bitmap, i);

  //print all bits for testing
  /*
  for (int i = 0; i < num; i++)
  {
    printf("%d: %lu\n",i, test_bit(bitmap,i));
  }
 */
 // check if bitmap will fit in one sector (SECTOR_SIZE > size(bitmap))
 if(SECTOR_SIZE >= size)
 {
     //printf("SECTOR_SIZE >= size -> %d > %lu", SECTOR_SIZE, size);
     if(Disk_Write(start, bitmap)<0)
          {
            dprintf("Error initializing bitmap, func=bitmap_init\n");
          }
	  else{
	    dprintf("...bitmap wrote to disk successfully using 1 sector to store, func=bitmap_init\n");
	  }


 }
 else
 {
     //printf("size > SECTOR_SIZE -> %lu > %d", size, SECTOR_SIZE );
     char buff[SECTOR_SIZE];
     int toXfr = size;//track total bytes to write to disk
     int numBytes = 0;
	 int i = -1;
	 int numSectorUsed = 0;

     for (i = 0; i<= size; i+=SECTOR_SIZE)
      {
        if(toXfr>SECTOR_SIZE)
        {
            numBytes = SECTOR_SIZE;
        }
        else
        {
            numBytes = toXfr;
        }
        memcpy(buff, &bitmap[i], numBytes);//copy to buff numBytes of bitmap
        if(Disk_Write(start++, buff)<0)
          {
            dprintf("Error initializing bitmap");
          }
		 numSectorUsed +=1;
        toXfr = toXfr - numBytes;//update number of bytes remaining to write to disk

        //for testing
        /*
        for(int y = 0; y < numBytes; y++)
        {
            printf("%d",buff[y]);
        }

        printf("\n");
        printf("Copied %d bytes, %d remaining\n", numBytes, toXfr);
        */
      }
		dprintf("...bitmap written to disk using %d sectors to store on disk, func=bitmap_init\n", numSectorUsed);
 }
  free(bitmap);
  dprintf("... mem freed for bitmap, func=bitmap_init\n");
}

// set the first unused bit from a bitmap of 'nbits' bits (flip the
// first zero appeared in the bitmap to one) and return its location;
// return -1 if the bitmap is already full (no more zeros)
static int bitmap_first_unused(int start, int num, int nbits)
{
  /* YOUR CODE */

  dprintf("... bitmap_first_unused called\n");

  char buff[SECTOR_SIZE];

  //determine number of sectors the bitmap occupies
  int secRemain = (nbits / CHARBITS)%SECTOR_SIZE;
  //int numSec = (nbits / CHARBITS)/SECTOR_SIZE;
  int numSec = num;
  dprintf("... numsec=%d\n", numSec);
  int found = 0;
  int firstUnused = -1;
  if(secRemain)
  {
      numSec += 1;
  }

  //determine number of bytes needed to represent bitmap with nbits
  int bmpARRLen = array_size(nbits);
  int currSec = start;

  //prep bitmap array
  char *bitmap;
  bitmap = (char*)calloc(bmpARRLen, sizeof(char));
  int index = 0; //track index in bmp where next chunk from buff will be stored
  int numBytes = bmpARRLen; //track remaining bytes to be copied to form complete bitmap
  int bytesToCopy = -1;

  for(int i = 0; i < numSec; i++)
  {
      //read each sector and build full bitmap
      if(Disk_Read(currSec, buff) < 0)
	  {
		  dprintf("... could not retrieve bitmap from disk in func bitmap_first_unused\n");
		  return -1;
	  }
      //copy buff to bitmap
      index = SECTOR_SIZE * i;
      if(numBytes<=SECTOR_SIZE)
      {
          bytesToCopy = numBytes;
      }
      else
      {
          bytesToCopy = SECTOR_SIZE;
          numBytes -= SECTOR_SIZE;
      }
      memcpy(&bitmap[index], buff, bytesToCopy);
  }

  //search for first bit equal to 0
  for(int i =0; i < nbits; i++)
  {
      //if equal to 0 set bit and return i
      if (test_bit(bitmap, i) == 0)
      {
          //set ith bit to 1
          set_bit(bitmap, i);
          found = 1;
          firstUnused = i;
      }
      if(found){
		  dprintf("... found unused bit in bitmap at index %d, func=bitmap_first_unused\n", firstUnused);
		  break;
	  }
  }

  //write new bit map to disk
  numBytes = bmpARRLen;
  currSec = start;
  index = 0;
  for(int i = 0; i < numSec; i++)
  {
      //check if remaining bytes to be copied (numBytes) is less than sector size
      if(numBytes <= SECTOR_SIZE)
      {
          bytesToCopy = numBytes;
      }
      else
      {
          bytesToCopy = SECTOR_SIZE;
      }
      //copy from bitmap to buff
      memcpy(buff, &bitmap[index], bytesToCopy);
      //write to currSec full bitmap or part of full bitmap
      if(Disk_Write(currSec, buff) < 0) return -1;
      //update index, beginning of next section of bitmap to copy
      index = SECTOR_SIZE * i;
      //update remaining number of bytes needing to be written to disk
      numBytes -= bytesToCopy;
  }
  //free allocated memory of bitmap
  free(bitmap);

  //if unused is found return its index, else return -1
  if(found)
  {
      return firstUnused;
  }
  else
  {
	  dprintf("...no unused bits in bitmap, func=bitmap_first_unused\n");
      return -1;
  }
}

// reset the i-th bit of a bitmap with 'num' sectors starting from
// 'start' sector; return 0 if successful, -1 otherwise
static int bitmap_reset(int start, int num, int ibit)
{
	dprintf("... called bitmap_reset\n");
  /* YOUR CODE */
  char buff[SECTOR_SIZE];
 //determine bitmap length
 int bmpARRLen = -1;

 //check if num of bits is a multiple of 8, if there is a remainder then the neccessary length
 //of an array to hold num bits is 1 + (number of bits / bits in a char = 8) otherwise its just (number of bits / bits in a char = 8)
 bmpARRLen = num*SECTOR_SIZE;

 //initialize bitmap arrary with length equal to bmpARRLen
 char *bitmap;

 //allocate the neccessary bytes for the num size bitmap
 bitmap = (char *)calloc(bmpARRLen, sizeof(char));

 //determine number of sectors the bitmap occupies
 int numSec = num;

 //check if bitmap only occupies one sector
 if(numSec == 1)
 {
     //bitmap only ooccupies one sector, read the bitmap from start sector
     if(Disk_Read(start, buff) < 0) {
       dprintf("...cannot read bitmap from disk, func=bitmap_reset\n");
		   return -1;}

     //copy from buffer to bitmap
     memcpy(bitmap, buff, bmpARRLen);

 }
 else
 {
     for(int i = 0; i < numSec; i++)
     {
         int secRd = start + i;
         //read from sector
         if(Disk_Read(secRd, buff) < 0) {
			 dprintf("...cannot read bitmap from disk, func=bitmap_reset\n");
			 return -1;}
         //copy to bitmap
         int index = i * SECTOR_SIZE;

         memcpy(&bitmap[index], buff, SECTOR_SIZE);
     }
  }

  if(test_bit(bitmap, ibit) == 0)
  {
	  dprintf("...error cannot clear bit in %d index, func=bitmap_reset\n", ibit);
      return -1;
  }
  else
  {
      clear_bit(bitmap, ibit);
	  dprintf("...bit in %d index cleared successfully, func=bitmap_reset\n", ibit);
  }
  //bytes to transfer from bitmap to buffer then write to disk
  int toXfr = bmpARRLen;
  //track num bytes to write to disk for each write to disk
    int numBytes = -1;
  //write bitmap to memory
  for (int i = 0; i<= num; i+=SECTOR_SIZE)
      {
        if(toXfr>SECTOR_SIZE)//num bytes to write larger than sector size
        {
            numBytes = SECTOR_SIZE;
        }
        else
        {
            numBytes = toXfr;
        }
        memcpy(buff, &bitmap[i], numBytes);//copy to buff numBytes of bitmap
        if(Disk_Write(start++, buff)<0)
          {
            dprintf("...writing bitmap to disk, func=bitmap_reset\n");
            return -1;
          }
        toXfr = toXfr - numBytes;//update number of bytes remaining to write to disk

      }


  return 0;
}