algo/python/45_bitmap/bitmap.py
2019-01-08 20:44:21 +00:00

30 lines
705 B
Python

"""
Author: Wenru Dong
"""
from typing import Optional
class Bitmap:
def __init__(self, num_bits: int):
self._num_bits = num_bits
self._bytes = bytearray(num_bits // 8 + 1)
def setbit(self, k: int) -> None:
if k > self._num_bits or k < 1: return
self._bytes[k // 8] |= (1 << k % 8)
def getbit(self, k: int) -> Optional[bool]:
if k > self._num_bits or k < 1: return
return self._bytes[k // 8] & (1 << k % 8) != 0
if __name__ == "__main__":
bitmap = Bitmap(10)
bitmap.setbit(1)
bitmap.setbit(3)
bitmap.setbit(6)
bitmap.setbit(7)
bitmap.setbit(8)
for i in range(1, 11):
print(bitmap.getbit(i))