输出一个整型数据的二进制形式

一般人会考虑用位运算,程序代码如下:


#include<stdio.h>




void Print(int n)




...{


if(n==1||n==0)




...{


printf("%d",n);


return;


}


Print(n>>1);


printf("%d",n%2);


}




int main()




...{


int a;


scanf("%d",&a);


Print(a);


return 0;


}

我们现在用一种特别的方法.用位段,可以不用进行运算即可输出结果,首先我们用一个程序输出整型数据在内存中的形式,程序代码如下:


#include <stdio.h>


#include <stdlib.h>




typedef struct




...{


unsigned char bit_1 : 1;


unsigned char bit_2 : 1;


unsigned char bit_3 : 1;


unsigned char bit_4 : 1;


unsigned char bit_5 : 1;


unsigned char bit_6 : 1;


unsigned char bit_7 : 1;


unsigned char bit_8 : 1;


}bit;




int main()




...{


int *p_int=NULL, len=sizeof(int);


bit *p_bit=(bit *)malloc(len*sizeof(bit));


p_int=(int *)p_bit;


*p_int=0;


printf("Please input a int value! ");


scanf("%d",p_int);


while(len--)//从高位到低位依次输出


printf("%d%d%d%d%d%d%d%d ", (p_bit+len)->bit_1, (p_bit+len)->bit_2,


(p_bit+len)->bit_3, (p_bit+len)->bit_4,


(p_bit+len)->bit_5, (p_bit+len)->bit_6,


(p_bit+len)->bit_7, (p_bit+len)->bit_8) ;


printf(" ");


free(p_bit);


return 0;


}

如果要输出一个整型数据的二进制形式,对于小端的编译器,上面的即可,而大端编译器则需要将输出的顺序1-8颠倒一下即可.下面是适合大端的编译器.(VC++ 6.0是大端编译器)


#include <stdio.h>


#include <stdlib.h>




typedef struct




...{


unsigned char bit_1 : 1;


unsigned char bit_2 : 1;


unsigned char bit_3 : 1;


unsigned char bit_4 : 1;


unsigned char bit_5 : 1;


unsigned char bit_6 : 1;


unsigned char bit_7 : 1;


unsigned char bit_8 : 1;


}bit;




int main()




...{


int *p_int=NULL, len=sizeof(int);


bit *p_bit=(bit *)malloc(len*sizeof(bit));


p_int=(int *)p_bit;


*p_int=0;


printf("Please input a int value! ");


scanf("%d",p_int);


while(len--)


printf("%d%d%d%d%d%d%d%d ", (p_bit+len)->bit_8, (p_bit+len)->bit_7,


(p_bit+len)->bit_6, (p_bit+len)->bit_5,


(p_bit+len)->bit_4, (p_bit+len)->bit_3,


(p_bit+len)->bit_2, (p_bit+len)->bit_1) ;


printf(" ");


free(p_bit);


return 0;


}