Reverse bits of a given 32 bits unsigned integer.
For example, given input 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?
通过和 1 进行位与运算，可以得到最右边一位，由于是无符号整数，进行无符号右移操作。
将结果不断左移一位，然后加上最右边一位。
public class Solution {
public int reverseBits(int n) {
int result = 0;
for (int i = 0; i < 32; i++) {
result = (result << 1) + (n & 1);
n = n >>> 1;
}
return result;
}
}