Making File Names Unique

Problem Description

Given an array of strings names of size n. You will create n folders in your file system such that, at the ith minute, you will create a folder with the name names[i]. Since two files cannot have the same name, if you enter a folder name that was previously used, the system will have a suffix addition to its name in the form of (k), where k is the smallest positive integer such that the obtained name remains unique. Return an array of strings of length n where ans[i] is the actual name the system will assign to the ith folder when you create it.

Key Insights

• Each folder name must be unique.
• If a name already exists, we need to append a suffix in the format (k), where k is the smallest positive integer.
• We can use a hash set to track existing folder names efficiently.
• The challenge lies in generating the correct suffixes for duplicate names.

Space and Time Complexity

Time Complexity: O(n) Space Complexity: O(n)

Solution

To solve this problem, we will use a hash set to keep track of the folder names that have already been created. As we iterate through the list of names, we will check if the name is already in the set. If it is not, we simply add it to the set and move to the next name. If it is, we will keep incrementing a counter k to find the next unique name by appending (k) until we find a name that is not in the set. This ensures that we always generate the smallest positive integer suffix for duplicates.

Code Solutions