#include <stdio.h>
 
main()
{
hexa = 16;
			printf("enter decimal number: ");
 
			scanf("%d",&deci);
 
			for (ctr = 1; ctr<=deci; ctr++)
 
			quotient = deci / hexa;
 
                        printf("Equivalent in Hexadecimal is %d",quotient);
 
 
			getche();
                   }

int main()
{
    char buf[255] = {0};
    int x = 1234;
    sprintf(buf,"%X", x);
    printf("%s\n", buf);
    return 0;
}

#include <stdio.h>
 
int main(void)
{
   int hexa = 16, deci, quotient, ctr;
   printf("enter decimal number: ");
   scanf("%d",&deci);
 
   for (ctr = 1; ctr<=deci; ctr++)
      quotient = deci / hexa;
 
   printf("Equivalent in Hexadecimal is %d",quotient);
   printf("\n\n Try this for Hexadecimal: %X", deci);   
 
   getche();
   return 0;
}
 
Good luck with your studies.

#include <stdio.h>
 
 
int main(void)  {
 
 
   int ctr, bin, quotient, deci=0, binary = 2;
   float rem;
   char mark_magic;
 
 
 
 
 
         gotoxy(28,9);printf("enter decimal number: ");
 
         scanf("%d",&deci);
         quotient = deci / binary;
 
         printf("Equivalent in Binary is ");
 
	 for(bin=0; bin <=3; bin++)
	 {
	    printf("%d",deci % 2);
            deci = deci / 2;
         }
 
 
 
         getchar();
}

void printB( int num )
{
     if( num == 0 )
         return;
     else
     {
         printB( num / 2 );
         printf("%d", num % 2 );
     }
}

printB( 23 );
 
/* my output
10111
*/