//BINARY DECIMAL AND HEXADECIMAL OPERATIONS

#include<stdio.h>
#include<math.h>
int bintodec(int);
int dectobin(int);
void bintohex(int);


void main()
{
int opt,bin,dec,hex;
clrscr();
do
  {
  printf("1.Binary to Decimal\n2.Decimal to Binary\n");
  printf("3.Binary to Hexadecimal\n4.Exit\n");
  printf("Enter any option\n");
  scanf("%d",&opt);
   switch(opt)
	    {
	    case 1:
		    {
			//BINARY TO DECIMAL
		    printf("Enter the binary number\n");
		    scanf("%d",&bin);

		    dec=bintodec(bin);
		    printf("Decimal Equvalent no is: %d",dec);

		    getch();
		    break;
		    }
	    case 2:
		    {
			//DECIMAL TO BINARY
		    printf("Enter the decimal number\n");
		    scanf("%d",&dec);

		    bin=dectobin(dec);

		    printf("Binary Equvalent no is: %d",bin);
		    getch();
		    break;
		    }
	    case 3:
		    {
			//BINARY TO HEXADECIMAL
		    printf("Enter the binary number\n");
		    scanf("%d",&bin);

		    bintohex(bin);
		    break;
		    }
	    case 4:
		    {
		    exit();
		    break;
		    }
	    default:
		    {
		    printf("Invalid Entry!\n");
		    getch();
		    }

	    }
  clrscr();
  }while(opt!=4);
}
int bintodec(int bin)
    {
    int i,dec=0,num;
    for(i=0;bin!=0;i++)
	  {
	  num=bin%10;
	  dec+=num*pow(2,i);
	  bin=bin/10;
	  }

    return(dec);
    }
int dectobin(int dec)
    {
    int bin=0;
    while(dec!=0)
	    {
	    bin=bin*10;
	    bin+=dec%2;
	    dec=dec/2;
	    }
    return(bin);
	 }
void bintohex(bin)
	 {
	 int i,j,dec,hex,num[20];
			//BINARY TO DECIMAL
	 dec=bintodec(bin);
			//DECIMAL TO HEXADECIMAL

		 for(i=0;dec!=0;i++)
			 {
			 if(dec>=0&&dec<=15)
			 {
			 num[i]=dec;
			 dec=0;
			 }
			 else
				{
				num[i]=dec%16;
				dec=dec/16;
				}
			 }
		  printf("Hexadecimal Equvalent no: ");
		  for(j=i-1;j>=0;j--)
			 {
			 if(num[j]>=10&&num[j]<=15)
			 {
			 switch(num[j])
				{
				case 10:
					  printf("A");
				case 11:
					  printf("B");
				case 12:
					  printf("C");
				case 13:
					  printf("D");
				case 14:
					  printf("E");
				case 15:
					  printf("F");
				}
			 }
			 else
				 printf("%d",num[j]);

			 }
		 getch();
		 return;


	 }

/*SAMPLE OUTPUT
1.Binary to Decimal
2.Decimal to Binary
3.Binary to Hexadecimal
4.Exit
Enter any option
1
Enter the binary number
1001
Decimal Equvalent no is: 9
_________________________

1.Binary to Decimal
2.Decimal to Binary
3.Binary to Hexadecimal
4.Exit
Enter any option
2
Enter the decimal number
15
Binary Equvalent no is: 1111
_________________________

1.Binary to Decimal
2.Decimal to Binary
3.Binary to Hexadecimal
4.Exit
Enter any option
3
Enter the binary number
1011
Hexadecimal Equvalent no: BCDEF

*/