# Problem Definition

## Description

Write a method duplicate to find the repeated or duplicate elements in an array. This method should return a list of repeated integers in a string with the elements sorted in ascending order (as illustrated below).

duplicate({1,3,4,2,1}) --> "[1]"

duplicate({1,3,4,2,1,2,4}) --> "[1, 2, 4]"

Note: You may use toString() method to return the standard string representation of most data structures, and Arrays.sort() to sort your result.

## Notes