The substring() method in Java is a powerful tool for extracting portions of a string. It allows you to create a new string based on the characters within a specified range of an existing string.

// Time Complexity: O(n²) (due to substring creation and window reset) } else if (right == s.length() - 1 && !(map.containsKey(s.substring(left, right + 1)))) { map ...

Most Java programmers have used the java.util.StringTokenizer class at some time or another. It is a handy class that basically tokenizes (breaks) the input string based on a separator, and supplies ...