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?
Related problem: Reverse Integer
一刷
有个很简单的做法，就是从尾部开始，逐渐构造一个新的数组。注意，由于是32 bit unsigned integer, 右移用>>>，表示无符号右移
public class Solution {
// you need treat n as an unsigned value
public int reverseBits(int n) {
int res = 0;
for(int i=0; i<32; i++){
res += n&1;
n = n >>>1;
if(i<31){
res = res<<1;
}
}
return res;
}
}
