无聊的刷题笔记

Reverse Bits

LeetCode 190

Reverse bits of a given 32 bits unsigned integer.

Example:

Input: 43261596
Output: 964176192
Explanation: 43261596 represented in binary as 00000010100101000001111010011100,
return 964176192 represented in binary as 00111001011110000010100101000000.

Follow up:
If this function is called many times, how would you optimize it?

class Solution {
public:
uint32_t reverseBits(uint32_t n) {
uint32_t ans=0;
for (int i=0;i<32;i++){
if (n&1==1) {
ans = (ans<<1) + 1;
}else{
ans = ans<<1;
}
n = n>>1;
}
return ans;
}
};
class Solution:
# @param n, an integer
# @return an integer
def reverseBits(self, n):
return int('{:032b}'.format(n)[::-1], 2)