From Swift Algorithms & Data Structures - 1st Edition, download the source code examples in Xcode Playground format. These standalone files are great for sharing and experimentation. Popular topics include: Big O Notation, Linked Lists, Hash Tables, Binary Search Trees, Graphs, Queues and others. Optimized for Xcode 7.3 / Swift 2.2.
(See Xcode 8.0 / Swift 3.0 version here)