Reverse bits of an 32 bit unsigned integer
x = 0,
00000000000000000000000000000000 => 00000000000000000000000000000000
x = 3,
00000000000000000000000000000011 => 11000000000000000000000000000000
Since java does not have unsigned int, use long
NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a doubt? Checkout Sample Codes for more details.