Given a number, such as 2, how would I reverse the bits assuming it is represented in 32-bits?
Take 1 for example, as unsigned 32-bits is 00000000000000000000000000000001 and doing the flipping we get 11111111111111111111111111111110 which in turn is 4294967294
I've tried the following but it is not working.
numElements = int(raw_input())
for i in range(0,numElements):
x = int(raw_input())
print int(bin(x)[:1:-1], 2)
Use XOR against a number with all 32 bits set to one:
mask = 2 ** 32 - 1
x = int(raw_input())
print format(x ^ mask, '032b')
^ is the bitwise XOR operator.
I used the format() function to produce a 0-padded 32-bit binary representation, it is far more flexible than bin().
Demo:
>>> mask = 2 ** 32 - 1
>>> format(mask, '032b')
'11111111111111111111111111111111'
>>> x = 1
>>> x ^ mask
4294967294
>>> format(x ^ mask, '032b')
'11111111111111111111111111111110'
