Leetcode: 190. Reverse Bits(JAVA)

【问题描述】

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as00111001011110000010100101000000).

Follow up:

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

Related problem: Reverse Integer

【思路】

类似于整数反转，首先按位与取最后一位后，依次右移1位。同时将结果左移1位，按位或。

【代码】

public class Solution {
// you need treat n as an unsigned value
public int reverseBits(int n) {
int result = 0;
int i = 0;
while (i < 32) {
int temp = n & 0x01;
n = n >> 1;

result = (result << 1) | temp;
i++;
}
return result;
}
}