Crosswords Generator

A simple algorithm for generating crosswords with Swift.
Based on Python Crossword Puzzle Generator.

Installation

CocoaPods:

pod 'CrosswordsGenerator'

Manual:

Copy CrosswordsGenerator.swift, Array2D.swift, ArrayShuffle.swift files to your project.

Using

Initialization and crosswords generation:

let generator = CrosswordsGenerator(columns: 10, rows: 10, maxLoops: 2000, words: ["saffron", "pumpernickel", "leaven", "coda", "paladin", "syncopation", "albatross", "harp", "piston", "caramel", "coral", "dawn", "pitch", "fjord", "lip", "lime", "mist", "plague", "yarn", "snicker"])
generator.generate()

To get result:

let result = crosswordsGenerator.result

The result is an array of structures:

public struct Word {
	public var word = ""
	public var column = 0
	public var row = 0
	public var direction: WordDirection = .Vertical
}

The sample of working:

--- Words ---
["pumpernickel", "syncopation", "albatross", "saffron", "paladin",
"caramel", "snicker", "leaven", "piston", "plague", "coral", "pitch",
"fjord", "coda", "harp", "dawn", "lime", "mist", "yarn", "lip"]

--- Result ---
pumpernickel-
---a-------e-
---l-------a-
caramel-f--v-
o--d----j--e-
r--i----o--n-
a-snicker----
l----o--dawn-
-----d-------
----harp-----
-------------
-------------
-------------

To generate the best crosswords in 10 attempts:

let crosswordsGenerator = CrosswordsGenerator()
crosswordsGenerator.words = ["saffron", "pumpernickel", "leaven", "coda", "paladin", "syncopation", "albatross", "harp", "piston", "caramel", "coral", "dawn", "pitch", "fjord", "lip", "lime", "mist", "plague", "yarn", "snicker"]
crosswordsGenerator.columns = 10
crosswordsGenerator.rows = 10
	
var bestResult: Array = Array()
let attempts = 10
		
for var i: Int = 0; i < attempts; ++i {
	crosswordsGenerator.generate()
	let result = crosswordsGenerator.result
			
	if result.count > bestResult.count {
		bestResult.removeAll()
		for word in result {
			bestResult.append(word)
		}
	}
}

To generate the best crosswords in 60 seconds:

let crosswordsGenerator = CrosswordsGenerator()
crosswordsGenerator.words = ["saffron", "pumpernickel", "leaven", "coda", "paladin", "syncopation", "albatross", "harp", "piston", "caramel", "coral", "dawn", "pitch", "fjord", "lip", "lime", "mist", "plague", "yarn", "snicker"]
crosswordsGenerator.columns = 10
crosswordsGenerator.rows = 10
		
var bestResult: Array = Array()
let startTime = NSDate()
let timeInterval: NSTimeInterval = 10
		
while (fabs(startTime.timeIntervalSinceNow) < timeInterval) {
	crosswordsGenerator.generate()
	let result = crosswordsGenerator.result
			
	if result.count > bestResult.count {
		bestResult.removeAll()
		for word in result {
			bestResult.append(word)
		}
	}
}

Also we have option fillAllWords. After generation of crosswords you can fill words to grid in random places that have not intersections. For example:

let crosswordsGenerator = CrosswordsGenerator(columns: 15, rows: 15, words: ["beijing", "havana", "rome", "paris", "amsterdam"])
crosswordsGenerator.fillAllWords = true
crosswordsGenerator.generate()

amsterdam-b-h--
-----o----e-a--
-----m----i-v--
-----e----j-a--
paris-----i-n--
----------n-a--
----------g----
---------------
---------------

In this repository you can find sample of working of this algorithm. Feel free. Happy coding!