/* Given a string, compute recursively the number of times lowercase "hi" * appears in the string, however do not count "hi" that have an 'x' * immedately before them. */ public int countHi2(String str) { if(str.length() <= 1) return 0; if(str.length() > 2 && str.substring(0, 3).equals("xhi")) return countHi2(str.substring(3)); if(str.substring(0, 2).equals("hi")) return 1 + countHi2(str.substring(2)); return countHi2(str.substring(1)); }