gistfile1.java

import java.util.ArrayList;

/**
 * Created by ayberk on 2/3/15.
 */
public class sdfsf
{
    private static ArrayList<String> combs = new ArrayList<String>();

    public static void setCombs(String initial) {
        setCombHelper(initial.toCharArray());
    }

    private static void setCombHelper(char[] pattern) {
        int first = leftMostUnknown(pattern);
        if (first < 0) {
            combs.add(new String(pattern));
            return;
        }

        pattern[first] = '0';
        setCombHelper(pattern.clone());
        pattern[first] = '1';
        setCombHelper(pattern.clone());
    }

    private static int leftMostUnknown(char[] pattern)
    {
        for (int i=0; i<pattern.length; i++) {
            if (pattern[i] == '?') {
                return i;
            }
        }

        return -1;
    }

    public static void main(String[] args)
    {
        String s = "01010?101?";

        setCombs(s);

        for (String x : combs) {
            int foo = Integer.parseInt(x, 2);
            System.out.println(x + ": "+ foo);
        }
    }
}