/* Given a non-empty string like "Code" return a string like "CCoCodCode". */ public String stringSplosion(String str) { int size = (str.length() * (str.length() + 1)) / 2; char[] result = new char[size]; int index = 0; for(int i = 0; i < str.length(); i++) { for(int j = 0; j <= i; j++) { result[index] = str.charAt(j); index++; } } return new String(result); }