二进制反序可以通过多种方法实现,以下是常见的几种方法及其实现方式:
一、逐位交换法(适用于小数据量)
通过逐位提取最低位并重新组合实现逆序。例如,将32位整数逆序可分为以下步骤:
1. 将整数右移1位,最低位移到最高位;
2. 使用按位或运算将最低位插入到结果的高位;
3. 记录移动位数,最后补全高位零。
示例代码(C语言):
```c
include
unsigned int reverse32(unsigned int v) {
unsigned int r = 0, s = 0;
while (v) {
r <<= 1;
r |= v & 1;
v >>= 1;
s++;
}
return r << s;
}
int main() {
unsigned int num = 0b110000111001;
printf("Original: 0b%08Xn", num);
printf("Reversed: 0b%08Xn", reverse32(num));
return 0;
}
```
二、分治递归法(适用于大数据量)
将整数按位分组(如每2位一组),递归交换每组内的位。例如:
1. 每2位一组进行交换(如00变01,11变10);
2. 递归处理剩余位。
示例代码(C语言):
```c
include
unsigned int reverse16(unsigned int v) {
v = (v & 0xFF00) | (v >> 16);
v = (v & 0x00FF) | (v >> 8);
v = (v & 0x0000FF) | (v >> 4);
v = (v & 0x0F00FF) | (v << 4) | (v >> 12);
v = (v & 0x00F0FF) | (v << 12) | (v >> 8);
v = (v & 0x0000F0FF) | (v << 8) | (v >> 4);
v = (v & 0x00000F00) | (v << 4) | (v >> 12);
v = (v & 0x000000FF) | (v << 12) | (v >> 8);
return v;
}
unsigned int reverse32(unsigned int v) {
return reverse16(v) | reverse16(v >> 16);
}
int main() {
unsigned int num = 0b110000111001;
printf("Original: 0b%08Xn", num);
printf("Reversed: 0b%08Xn", reverse32(num));
return 0;
}
```
三、位运算优化法(高效实现)
通过位运算组合实现逆序,减少循环次数。例如:
1. 每4位一组进行交换(如0001变1000,0011变1100);
2. 递归处理剩余位。
示例代码(C语言):
```c
include
unsigned int reverse4(unsigned int v) {
v = ((v & 0xF0) >> 4) | ((v & 0x0F) << 4);
v = ((v & 0xC0) >> 2) | ((v & 0x30) << 2);
v = ((v & 0x90) >> 1) | ((v & 0x33) << 1);
v = ((v & 0x55) >> 1) | ((v & 0xAA) << 1);
return v;
}
unsigned int reverse32(unsigned int v) {
return reverse4(v) | reverse4(v >> 16);
}
int main() {
unsigned int num = 0b110000111001;
printf("Original: 0b%08Xn", num);
printf("Reversed: 0b%08Xn", reverse32(num));
return 0;
}
```
四、Python实现(简洁示例)
Python中可通过字符串切片实现快速逆序:
```python
def reverse_binary(num):
binary_str = bin(num)[2:]
reversed_binary_str = binary_str[::-