/* Given a string, compute recursively (no loops) the number of "11" * substrings in the string. The "11" substrings should not overlap. */ public int count11(String str) { if(str.length() <= 1) return 0; if(str.substring(0, 2).equals("11")) return 1 + count11(str.substring(2)); return count11(str.substring(1)); }