countHi

public int countHi(String str) {
    int count = 0;
  if (str.isEmpty()){
    return 0;
  }
   if (str.length() < 2) return 0;

  if(str.charAt(0)=='h'&&str.charAt(1)=='i'){
    count= 1;
  }else {
  count=0;
  }
  return count+countHi(str.substring(1));
}

//countHi("xxhixx") → 1
//countHi("xhixhix") → 2
//