Algo Hub is a completely non-profitable platform for the lover of data structure and algorithm, absolutely free and open to everyone who is keen on it.
Include:
Linked List / Stack / Queue / Tree / BST / BT / Heap
Moreover, all the source code in this app is under MIT license, feel free to copy and paste without permission.
Note: For now, all data structure and algorithm is finished by Swift. It is promoted for all the users to do it using other languages like python, C, C++, C#, Go, Java, PHP, Javascript and so on. Also submitting the problem & solution code and recorrecting the exist code is welcome.