bit-array study

bitset.py

class BitSet:
	"""
	bit-array implementation
	"""
	def __init__(self, size):
		# same as size / 32 (2^5)
		self.arr = [0] * ((size >> 5) + 1)


	def get(self, number):
		i = number >> 5

		# number & 31
		bit_i = number & 0x1F

		p = 1 << bit_i
		print('get', self.arr[i], p)

		return (self.arr[i] & p) != 0

	def set(self, number):
		i = number >> 5

		# number & 31 / 0-31 = 32
		bit_i = number & 0x1F

		# move bit_i from 1 to the right
		# 1 << 3 = 1 * 2^3
		# 1 is 0000 0001
		# 1 << 3 is 0000 0100 => 8
		p = 1 << bit_i
		
		print('!', i, self.arr[i], p)
		self.arr[i] |= p
		print('set', i, self.arr[i])
		


# store 32000 bits + 1
# since 1 int has 32bits, 32000 bits will store
# 1000 ints
bs = BitSet(32*1000)

bs.set(25)
bs.set(31)

print(bs.get(10))
print(bs.get(31))