Swift implementation of the longest common subsequence (LCS) algorithm
SwiftLCS
SwitLCS provides an extension of Collection
that finds the indexes of the longest common subsequence with another collection.
The longest common subsequence (LCS) problem is the problem of finding the longest subsequence common to all sequences in a set of sequences (often just two sequences). It differs from problems of finding common substrings: unlike substrings, subsequences are not required to occupy consecutive positions within the original sequences.
The project is based on the Objective-C implementation of NSArray+LongestCommonSubsequence.
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Installation
CocoaPods
CocoaPods is the dependency manager for Swift and Objective-C Cocoa projects. It has over ten thousand libraries and can help you scale your projects elegantly.
Add this to your Podfile:
use_frameworks!
pod 'SwiftLCS'
Carthage
Carthage builds your dependencies and provides you with binary frameworks, but you retain full control over your project structure and setup.
Add this to your Cartfile:
github "Frugghi/SwiftLCS"
Swift Package Manager
The Swift Package Manager is a tool for managing the distribution of Swift code. It’s integrated with the Swift build system to automate the process of downloading, compiling, and linking dependencies.
Add SwiftLCS
to your Package.swift dependencies:
import PackageDescription
let package = Package(
dependencies: [
.Package(url: "https://github.com/Frugghi/SwiftLCS.git", majorVersion: 1, minor: 3)
]
)
Manual
Include SwiftLCS.swift
into your project.
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Documentation
The API documentation is available here.
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Usage
Import the framework:
import SwiftLCS
String
let x = "abracadabra"
let y = "yabbadabbadoo"
let z = x.longestCommonSubsequence(y) // abadaba
Array
let x = [1, 2, 3, 4, 5, 6, 7]
let y = [8, 9, 2, 10, 4, 11, 6, 12]
let z = x.longestCommonSubsequence(y) // [2, 4, 6]
Indexes
let x = [1, 2, 3, 4, 5, 6, 7]
let y = [8, 9, 2, 10, 4, 11, 6, 12]
let diff = x.diff(y)
// diff.commonIndexes: [1, 3, 5]
// diff.addedIndexes: [0, 1, 3, 5, 7]
// diff.removedIndexes: [0, 2, 4, 6]
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Objective-C
Object comparison of Objective-C objects is done through the isEquals:
method, so be sure that the implementations is correct otherwise SwiftLCS
will not return the correct indexes.
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License
SwiftLCS is released under the MIT license. See LICENSE for details.