Thread: reverse bit with switch

What is wrong with my switch....I get the same weird value for x three times

Code:

#include <stdio.h>
#define N (int)(8*sizeof(int))
#define sizeofInt 32

void printbits(unsigned int t);

int main(void)
{
    unsigned int x;
	int k,i,flip,mask,flag;

	flip=0;
    mask=1; 
	
	for (k=0;k<3;k++)
	{
		switch(x)
		{
		case 1:   x= 0xA4420810; break;
		case 2:   x= 0xfedcba98; break;
		case 3:   x= 0x0f0f0f0f; break;
		}
	
    printf("x:%X\n",x);
	printbits(x);

    flag= x;
    for (i=0; i<sizeofInt; i++)
    {
       flip <<= 1;
       flip |= flag & mask;
       flag >>= 1;
    }
 	
	printbits(flip);
	putchar('\n');
	}

return 0;
}
void printbits(unsigned int t)
{
	int k;

	for (k=0;k<N;k++,t<<=1)
	{
		putchar('0'+((0x80000000 &t)>>(N-1)) );
		if ((k+1)%4==0) putchar(' ');
	}
	putchar('\n');

	return;
}

Code tags added by Kermi3

thanks.........it works

I need to to put all codes to flip the bit into a reverse() function that returns an unsigned int.

How can I do that?

Here are my codes:

---------------------------------------------------------------
#include <stdio.h>
#define N (int)(8*sizeof(int))
#define sizeofInt 32

void printbits(unsigned int t);

int main(void)
{
unsigned int x;
int k,i,flip,mask,flag;

flip=0;
mask=1;

for (k=0;k<3;k++)
{
switch(k)
{
case 0: x= 0xA4420810; break;
case 1: x= 0xfedcba98; break;
case 2: x= 0x0f0f0f0f; break;
}

printf("x:%X\n",x);
printbits(x);

flag= x;
for (i=0; i<sizeofInt; i++)
{
flip <<= 1;
flip |= flag & mask;
flag >>= 1;
}

printbits(flip);
putchar('\n');
}

return 0;
}
void printbits(unsigned int t)
{
int k;

for (k=0;k<N;k++,t<<=1)
{
putchar('0'+((0x80000000 &t)>>(N-1)) );
if ((k+1)%4==0) putchar(' ');
}
putchar('\n');

return;
}

ok ok ........I am now using code tags

Code:

#include <stdio.h>
#define N (int)(8*sizeof(int))
#define sizeofInt 32

void printbits(unsigned int t);

int main(void)
{
    unsigned int x;
	int k,i,flip,mask,flag;

	flip=0;
    mask=1; 
	
	for (k=0;k<3;k++)
	{
		switch(k)
		{
		case 0:   x= 0xA4420810; break;
		case 1:   x= 0xfedcba98; break;
		case 2:   x= 0x0f0f0f0f; break;
		}
	
    printf("x:%X\n",x);
	printbits(x);

    flag= x;
    for (i=0; i<sizeofInt; i++)
    {
       flip <<= 1;
       flip |= flag & mask;
       flag >>= 1;
    }
 	
	printbits(flip);
	putchar('\n');
	}

return 0;
}
void printbits(unsigned int t)
{
	int k;

	for (k=0;k<N;k++,t<<=1)
	{
		putchar('0'+((0x80000000 &t)>>(N-1)) );
		if ((k+1)%4==0) putchar(' ');
	}
	putchar('\n');

	return;
}

I don't want to use xor...because it will be too easy.....anyway I was able to blip the bits but I want to put the codes in a function called reverse().....how can do that?