Thread: decimal to binary

Or, if you don't want to look like a total newb:

Code:

#include <stdio.h>

int main( int argc, char **argv )
{
  int num;
  char binary[9];
  int i, x;

  if ( argc > 1 )
    num = atoi( argv[1] );
  else
  {
    printf( "no decimal specified on command line\n" );
    return (1);
  }

  for ( i=7, x=1; i > -1; i--, x *= 2 )
  {
    if ( num & x )
      binary[i] = '1';
    else
      binary[i] = '0';
  }

  printf( "%s\n", binary );
}

or this:

Code:

int main() {
unsigned char x;
scanf("%d",&x);
do printf("%d",x%2?1:0); while (x=x>>1);
}

this does it in reverse order, and stops when the number's finished. ie: 0000 0001 would be 1, and 0001 1101 would be 10111. but it's an example
recursively:

Code:

int printbinary(unsigned char);
int main() {
unsigned char x;
scanf("%d",&x);
printbinary(x);
}
int printbinary(unsigned char x) {
if (!x) return 0;
printf("%d",x%2?1:0);
printbinary(x>>1);
}

Hasn't this been answered a slew of times already?

Code:

#include <stdio.h>
#include <stdlib.h>

int main ( void )
{
  int c = 10, i, j;
  char bTemp[8], bFinal[8];
  for ( i = 7, j = 0; i >= 0; i--, j++ ) {
    bTemp[i] = !!( c & ( 1 << i ) ); 
    bTemp[i] = bTemp[i] % 10 + '0';
    bFinal[j] = bTemp[i];
  }
  for ( i = 0; i < 8; i++ ) putchar ( bFinal[i] );
  return EXIT_SUCCESS;
}

-Prelude

Maybe you can give some comments to it:

Code:

#include <stdio.h>
#include <string.h>

#define PUFFER 256


void asctobin(void); /* converts ASCII-characters into binary digits */
void bintoasc(void); /* converts binary digits into ASCII characters */

unsigned char bin[]={1,2,4,8,16,32,64,128};

int main(void)
{
	char chose;

	for(chose=0;chose<40;chose++,printf("\n")) ; /* clear screen */

again:
	printf("Enter \'A\' to convert ASCII to binary or \'B\' to convert binary into ASCII: ");
	scanf("%c",&chose);
	if(chose=='A' || chose=='a') asctobin();
	else
	{
		if(chose=='B' || chose=='b') bintoasc();
		else{
			rewind(stdin); /* back to the begin of stdin; if more then one character was entered */
			goto again;
		} /* only accepts 'A','a','B' and 'b' as inputs */
	}

	return 0;
}


void asctobin(void)
{
        char *string,c;
	int count,len;

	printf("Enter string (max length: 255 characters): ");
	rewind(stdin); /* back to the begin of stdin */
	fgets(string,PUFFER-1,stdin);

	len=strlen(string);

	for(;len>0;len--) /* as often as the value for the length of the inputed string */
	{
		c=*string; /* the character string points to at the moment */
		for(count=7;count>=0;count--)
		{        
			if(c>=bin[count])
			{
				printf("1");
				c-=bin[count];
			}else
			printf("0");
		}
		*string++;
		printf(" ");
	}
}


void bintoasc(void)
{
	char *string,c;
	int count=0,len;


	printf("Enter digits (max 255):");
	rewind(stdin); /* back to the begin of stdin */
	fgets(string,PUFFER-1,stdin);

	len=strlen(string);

	for(;len>0;len--) /* as often as the value for the length of the inputed string */
	{
		if(*string=='1')
		{
			c+=bin[7-count];
			count++;
		}else 
		if(*string=='0') count++;

		if(count%8==0)
		{
			printf("%c",c);
			count=c=0;
		}

		*string++;
	}
}

klausi