// CSE 143, Autumn 2013
// This program demonstrates a recursive printBinary method that 
// prints the binary representation of an integer.
//
// We also wrote a recursive pow method today which is included below.

public class Binary {
    public static void main(String[] args) {
        printBinary(-4);       // 100
        System.out.println();
        printBinary(12);      // 1100
        System.out.println();
        printBinary(21);      // 10101
        System.out.println();
        printBinary(42);      // 101010
        System.out.println();
        printBinary(69743);   // 10001000001101111
        System.out.println();
    }
    
    // Prints the binary representation of the given integer.
    // For example, printBinary(42) prints 101010.
    // Precondition: n >= 0
    public static void printBinary(int n) {
    	if(n < 0) {
    		System.out.print("-");
    		printBinary(-n);
    	} else if ( n < 2) {
    	   System.out.print(n);
       } else {
    	   int last = n % 2;
    	   int rest = n / 2;
    	   // print the rest of the number
    	   printBinary(rest);
    	   System.out.print(last);
       }
    }
}