Swift 4.2 Migration

[kelvinlauKL]

Brief Intro

Every year, we go through the repository to make sure all the README and playgrounds are up-to-date with the latest Xcode.

Migration Procedure:

1. Choose a topic below that hasn't been checked off
2. Check the pull requests to see if anyone is working on your chosen topic
3. Make a pull request to let others know that you're currently working on your chosen topic

Remove code snippet at the top of each playground file:

// last checked with Xcode 9.0b4
#if swift(>=4.0)
   print("Hello, Swift 4!")
#endif

• Make sure the code for the topic compiles correctly with the latest Xcode 10.
• Make sure that the README.md file reflects the updated playground

Current Progress

• [x] 3Sum and 4Sum
• [x] AVL Tree
• [ ] All-Pairs Shortest Paths
• [x] Array2D
• [x] B-Tree
• [x] Binary Search Tree
• [x] Binary Search
• [x] Binary Tree
• [ ] Bit Set
• [x] Bloom Filter
• [x] Bounded Priority Queue
• [x] Boyer-Moore-Horspool
• [x] Breadth-First Search
• [ ] Brute-Force String Search
• [ ] Bubble Sort
• [x] Bucket Sort
• [ ] Comb Sort
• [ ] Combinatorics
• [x] Convex Hull
• [x] Count Occurrences
• [x] Counting Sort
• [x] Depth-First Search
• [x] Deque
• [x] Dijkstra Algorithm
• [ ] DiningPhilosophers
• [x] Egg Drop Problem
• [ ] Encode and Decode Tree
• [x] Fixed Size Array
• [x] Fizz Buzz
• [x] GCD
• [x] Graph
• [x] Hash Set
• [x] Hash Table
• [x] HaversineDistance
• [x] Heap Sort
• [x] Heap
• [x] Huffman Coding
• [ ] Insertion Sort
• [x] K-Means
• [x] Karatsuba Multiplication
• [x] Knuth-Morris-Pratt
• [x] Kth Largest Element
• [x] LRU Cache
• [x] Linear Regression
• [x] Linear Search
• [x] Linked List
• [ ] Longest Common Subsequence
• [x] Merge Sort
• [x] Miller-Rabin Primality Test
• [x] Minimum Edit Distance
• [x] Minimum Spanning Tree (Unweighted)
• [x] Minimum Spanning Tree
• [ ] MinimumCoinChange
• [x] Monty Hall Problem
• [x] Multiset
• [ ] Naive Bayes Classifier
• [ ] Octree
• [x] Ordered Array
• [ ] Ordered Set
• [x] Palindromes
• [ ] Priority Queue
• [x] QuadTree
• [x] Queue
• [ ] Quicksort
• [ ] Rabin-Karp
• [x] Radix Sort
• [ ] Radix Tree
• [ ] Red-Black Tree
• [x] Ring Buffer
• [ ] Rootish Array Stack
• [x] Run-Length Encoding
• [ ] Segment Tree
• [ ] Select Minimum Maximum
• [ ] Selection Sampling
• [x] Selection Sort
• [x] Set Cover (Unweighted)
• [ ] Shell Sort
• [ ] Shortest Path (Unweighted)
• [x] Shuffle
• [x] Shunting Yard
• [ ] Simulated Annealing
• [ ] Single-source Shortest Paths(Weighted)
• [ ] Skip-List
• [x] Slow Sort
• [x] Sorted Set
• [ ] Sparse Table
• [ ] Splay tree
• [x] Stack
• [x] Strassen Matrix Multiplication
• [ ] Ternary Search Tree
• [x] Threaded Binary Tree
• [ ] Topological Sort
• [ ] Treap
• [x] Tree
• [x] Trie
• [x] Two-Sum Problem
• [x] Union-Find
• [x] Z-Algorithm

[kelvinlauKL]

Closing since it's time for Swift 5.0 🗡