Check Duplicates in Array

Given an array of integers nums, for each index i, perform the following checks: Check if nums[i] has appeared on the left side of nums. If so, fill string1 at position i with '1', otherwise fill with '0'. Check if nums[i] will appear again on the right side of nums. If so, fill string2 at position i with '1', otherwise fill with '0'. Finally, return an array of the two binary strings [string1, string2]. Example Input 4 1 2 1 3