How to Remove Duplicates from an Unsorted Vector While Preserving Order Using STL?

Removing Duplicates from Unsorted Vector While Preserving Originality Using STL

Problem:
Locate an efficient solution to eliminate duplicates from a given unsorted vector while maintaining the original ordering.

Custom Approach:
The provided implementation utilizes a set to track unique elements. It iteratively checks each vector element, adding unique elements to a new vector and removing duplicates from the original vector.

STL Algorithm Approach:
A more streamlined solution leveraging STL algorithms is recommended. Employ the std::copy_if algorithm and define a predicate that tracks processed elements. Return false for already-processed elements and true otherwise.

Implementing the Predicate:
Create a struct called NotDuplicate with a boolean operator() method. This operator tracks elements through a set insertion. True is returned if the insertion succeeds (indicating a unique element).

Utilizing std::copy_if:
Utilize std::copy_if to iterate over the original vector, applying the NotDuplicate predicate. Unique elements will be copied to a new vector called uniqueNumbers. By referencing the NotDuplicate instance within std::copy_if, side-effects are avoided. This algorithm provides a cleaner and more efficient solution without the need to manually remove duplicates or maintain iterators.

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