#include<conio.h>
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
void main()
{
 int n,i=0,b,s=0,r;
 char ch='y';
 do
 {
  clrscr();
  gotoxy(40,10);
  printf("1.BINARY TO DECIMAL\n");
  gotoxy(40,12);
  printf("2.OCTAL TO DECIMAL\n");
  gotoxy(40,14);
  printf("3.HEXADECIMAL TO DECIMAL\n");
  gotoxy(40,16);
  printf("4.EXIT\n");
  gotoxy(40,18);
  printf("ENTER UR CHOICE 1/2/3/4");
  scanf("%d",&n);
  switch(n)
  {
   case 1:
	 clrscr();
	 printf("ENTER ANY NUMBER");
	 scanf("%d",&b);
	 while(b>0)
	 {
	  r=b%10;
	  s=s+r*pow(2,i);
	  i++;
	  b=b/10;
	 }
	 printf("IN DECIMAL %d",s);
	 break;
   case 2:
	 clrscr();
	 printf("ENTER ANY NUMBER");
	 scanf("%d",&b);
	 while(b>0)
	 {
	  r=b%10;
	  s=s+r*pow(8,i);
	  i++;
	  b=b/10;
	 }
	 printf("IN DECIMAL %d",s);
	 break;
   case 3:
	 clrscr();
	 printf("ENTER ANY NUMBER");
	 scanf("%d",&b);
	 while(b>0)
	 {
	  r=b%10;
	  s=s+r*pow(16,i);
	  i++;
	  b=b/10;
	 }
	 printf("IN DECIMAL %d",s);
	 break;
    case 4:
	 exit(0);
    default:
	 printf("ENTER UR CHOICE 1/2/3/4");
 }
 gotoxy(38,12);
 printf("WANT TO CONTINUE AGAIN y/n");
 ch=getche();
 }
 while(ch=='y' || ch=='Y');
 getch();
}