一段好玩的代码

这是编程之美上的一段代码，使用一个字节的空间，计算象棋中将帅的位置关系

这里是书中最简单的一个代码段：

//#include <stdio.h>

#include <iostream>

#define HALF_BITS_LENGTH 4

#define FULLMASK 255

#define LMASK (FULLMASK << HALF_BITS_LENGTH)//1111000

#define RMASK (FULLMASK >> HALF_BITS_LENGTH)//00001111

#define RSET(b,n) (b = ((LMASK & b) ^ n))

#define LSET(b,n) (b = ((RMASK & b) ^ (n << HALF_BITS_LENGTH)))

#define RGET(b) (RMASK & b)

#define LGET(b) ((LMASK & b) >> HALF_BITS_LENGTH)

#define GRIDW 3

int main()

{

unsigned char b = 0;

for(LSET(b,1); LGET(b) <= GRIDW * GRIDW;LSET(b,(LGET(b)+1)))

{

for(RSET(b,1); RGET(b) <= GRIDW * GRIDW;RSET(b,(RGET(b)+1)))

{

if(LGET(b)%GRIDW != RGET(b)%GRIDW)

{

std::cout<<"A = "<<LGET(b)<<"B= "<<RGET(b)<<std::endl;

//printf("A=%d,B = %d\n",LGET(b),RGET(b));

}

}

}

return 0;

}