leetcode_gym/_problems/reverseBits.md

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layout	title	last_solved	category	leetcode_url	status
page	Reverse Bits	Solved	Bits	https://leetcode.com/problems/reverse-bits	Solved

Problem

Reverse bits of a given 32 bits unsigned integer.

 

Example 1:

Input: 00000010100101000001111010011100
Output: 00111001011110000010100101000000
Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000.
Example 2:

Input: 11111111111111111111111111111101
Output: 10111111111111111111111111111111
Explanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10111111111111111111111111111111.

Solution

Try doing it by hand for a small test case like a number with 4 bits (see image).

{% highlight python %}

def reverseBits(self, n: int) -> int:

output, power = 0, 31

while n:
    output += (n&1) << power
    n>>=1
    power-=1

return output

{% endhighlight %}