(Hexadecimal to Binary Converter)
#include 
#include 
#include 
void main()
{
 char z[5],c;
 int i=0;
 clrscr();
 printf("Enter a hexadecimal no.");
 printf("
Number will be accepted if you press Ctrl-Z & then ENTER after inputting no.");
 printf("
NUMBER:- " );
 while ((c=getchar())!=EOF)
 {
 printf(" ");
 if (c=='1')
 printf("0001");
 else if (c=='2')
 printf("0010");
 else if (c=='3')
 printf("0011");
 else if (c=='4')
 printf("0100");
 else if (c=='5')
 printf("0101");
 else if (c=='6')
 printf("0110");
 else if (c=='7')
 printf("0111");
 else if (c=='8')
 printf("1000");
 else if (c=='9')
 printf("1001");
 else if (c=='A'||c=='a')
 printf("1010");
 else if (c=='B'||c=='b')
 printf("1011");
 else if (c=='C'||c=='c')
 printf("1100");
 else if (c=='D'||c=='d')
 printf("1101");
 else if (c=='E'||c=='e')
 printf("1110");
 else if (c=='F'||c=='f')
 printf("1111");
 else
 { printf("ERROR");
	getch();
	exit(0); }
 }
 printf("
		 is its binary equivalent.");
 getch();
}