xpython/code/int2binary.py at master · wp-lai/xpython · GitHub

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"""
Task:
 Converting decimal numbers to binary numbers

>>> convert_to_binary(25)
'0b11001'
>>> convert_to_binary(233)
'0b11101001'
>>> convert_to_binary(42)
'0b101010'
>>> convert_to_binary(0)
'0b0'
>>> convert_to_binary(1)
'0b1'
"""


# Solution 1:
# keep dividing by 2, store the remainder in a stack
# read in reverse order
defconvert_to_binary(number):
ifnumber==0:
return'0b0'

stack= []
whilenumber:
stack.append(number%2)
number=number//2
binary_str="0b"
whilestack:
binary_str+=str(stack.pop())
returnbinary_str


# Solution 2: using built-in function bin
defconvert_to_binary(number):
returnbin(number)


# Solution 3: using string formatting
defconvert_to_binary(number):
return'0b{:b}'.format(number)


# Solution 4: using bitwise operation
defconvert_to_binary(number):
ifnumber==0:
return'0b0'

stack= []
whilenumber:
stack.append(number&1) # append last bit
number=number>>1# remove last bit
binary_str="0b"
whilestack:
binary_str+=str(stack.pop())
returnbinary_str


# Solution 5: using recursion
defconvert_to_binary(number):
digit="01"
ifnumber<2:
return"0b"+digit[number]
else:
returnconvert_to_binary(number//2) +digit[number%2]


if__name__=='__main__':
importdoctest
doctest.testmod()