Originally Posted by ayat_Ace

hi mr shabbir
the answers i mean that you seems to me a very skillful experts so advise me to be good at assemly programming i mean that you know more than me about very powerful websites help me to improve my self in programming

thanks alot
could you send me your email please
my email : ayat_ace@yahoo.com

/* Decimal Integer to Binary String or Hexa String Convertor */

#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>

#define DEFAULTVAL 0

char* dec_to_binstr(int,int=DEFAULTVAL);
char* dec_to_hexstr(int,int=DEFAULTVAL);

void main()
  {
  int choice;
  unsigned int decqty,numbits;

  do{
    clrscr();
    printf("1. DEC TO BIN\t2. DEC TO HEX\n3. EXIT");
    printf("\nEnter choice :  ");
    scanf("%d",&choice);

    if(choice==1 || choice==2)
      {
      printf("\n\n\nEnter the Decimal Quantity :  ");
      scanf("%d",&decqty);
      printf("\nEnter a specific Number of Bits/Hexa-Digits if you want the O/P to contain a specific number of bits");
      printf("\n(Enter '0' (or DEFAULTVAL) to leave blank so that program calculates required number of bits) :  ");
      scanf("%d",&numbits);
      }

    switch(choice)
      {
      default:
        printf("\n\nINVALID CHOICE!! Please Try Again!!");
      case 1:
        printf("\n\nBinary Equivalent is :  %s",dec_to_binstr(decqty,numbits));
        break;
      case 2:
        printf("\n\nHexadecimal Equivalent is :  %s",dec_to_hexstr(decqty,numbits));
        break;
      case 3:
        break;
      }
    getch();
    }while(choice!=3);
  }

/* This Routine Converts a decimal Qty to binary Qty */
char* dec_to_binstr(int decnum,int numbits)
  {
  int i,j,k;
  char *result;
  char *temp;

  printf("\n\n\nEntered in Routine :  dec_to_binstr()");
  printf("\ndecnum = %d\tnumbits = %d",decnum,numbits);

  // Calculating Number of bits required
  for(i=0;pow(2,i)<abs(decnum);i++);

  printf("\nNo. of bits reqd (i) = %d",i);

  // Checking Whether 'numbits' provided in Call is adequate
  if(numbits!=DEFAULTVAL && numbits<i)
    return "ERROR!! Incorrect 'numbits' Specification during Call!!";

  // Allocating Memory for 'temp' & 'result'
  else if(numbits==DEFAULTVAL)
    // No 'numbits' provided in call
    {
    temp=(char*)malloc((i+1)*sizeof(char));
    result=(char*)malloc((i+1)*sizeof(char));
    }
  else
    // Function call has provided the 'numbits'
    // Assuming that 'numbits' involves the 1 extra character slot required
    // in case of signed integers
    {
    temp=(char*)malloc((numbits+1)*sizeof(char));
    result=(char*)malloc((numbits+1)*sizeof(char));
    }

  // Performing Intermediate processing on 'temp'
  for(j=0;decnum>0;j++)
    {
    temp[j]=char('0'+decnum%2);
    decnum=decnum/2;
    }

  // Padding Any Bits Remaining if at all with Zeroes
  for(;j<numbits;j++)
    temp[j]='0';
  temp[j]='\0';

  // Forming the 'result' string by String Reversal
  k=0;

  if(numbits==DEFAULTVAL)
    j=i-1;
  else
    j=numbits-1;

  for(;j>=0;j--,k++)
    result[k]=temp[j];
  result[k]='\0';

  return result;
  }

char* dec_to_hexstr(int decnum,int numbits)
  {
  int i,j,k;
  char *result;
  char *temp;
  int numtemp;
  
  printf("\n\n\nEntered in Routine :  dec_to_hexstr()!!");
  printf("\ndecnum = %d\tnumbits = %d",decnum,numbits);

  // Calculating Number of Hexa-digits required
  for(i=0;pow(16,i)<abs(decnum);i++);

  printf("\nNo. of Hexa-digits reqd (i) = %d",i);

  // Checking Whether 'numbits' provided in Call is adequate
  if(numbits!=DEFAULTVAL && numbits<i)
    return "ERROR!! Incorrect 'numbits' Specification during Call!!";

  // Allocating Memory for 'temp' & 'result'
  else if(numbits==DEFAULTVAL)
    // No 'numbits' provided in call
    {
    temp=(char*)malloc((i+1)*sizeof(char));
    result=(char*)malloc((i+1)*sizeof(char));
    }
  else
    // Function call has provided the 'numbits'
    // Assuming that 'numbits' involves the 1 extra character slot required
    // in case of signed integers
    {
    temp=(char*)malloc((numbits+1)*sizeof(char));
    result=(char*)malloc((numbits+1)*sizeof(char));
    }

  // Performing Intermediate processing on 'temp'
  for(j=0;decnum>0;j++)
    {
    numtemp=decnum%16;
    if(numtemp>=10)
      temp[j]=char('A'+(numtemp-10));
    else
      temp[j]=char('0'+numtemp);
    decnum=decnum/16;
    }

  // Padding Any Bits Remaining if at all with Zeroes
  for(;j<numbits;j++)
    temp[j]='0';
  temp[j]='\0';

  // Forming the 'result' string by String Reversal
  k=0;

  if(numbits==DEFAULTVAL)
    j=i-1;
  else
    j=numbits-1;

  for(;j>=0;j--,k++)
    result[k]=temp[j];
  result[k]='\0';

  return result;
  }

Originally Posted by rai_gandalf

Very useful thread, this one. The thing is one becomes so proficient in programming & concerned with advanced implementation issues, that one often forgets small snippets & nuggets of code such as this. So, Thx a lot for it.

Originally Posted by rai_gandalf

Waise, I developed a Decimal Integer to Binary String or Hexa String Convertor. I have put the source code here ....