Removing Duplicates from an Array (Set-Like Logic)

This lesson covers removing duplicates from an array in C, so you understand the basics of set-like logic. It's for anyone searching "C array deduplication implementation."

C has no dedicated Set type, but you can build duplicate-free data by adding "only values not already present" into a new array. Checking whether a value is already included before adding it is the basic idea.

The example checks whether each element of nums is already present in the unique array using an inner for loop, and adds it if not. This is a simple implementation that uses a nested loop for both searching and adding.

A common early mistake is not accounting for processing speed with a large amount of data. This method's processing time grows proportional to the square of the element count, making it unsuitable for a large dataset — a faster method would need something like a hash table.

In real projects, understanding the efficiency of simple algorithms like this matters, since C often runs in constrained environments.