54652.swift

//puzzling.stackexchange.com/posts/54652/
struct Square {
	var up: UInt8 = 0
	var left: UInt8 = 0
	var down: UInt8 = 0
	var right: UInt8 = 0
	var rotation: Int = 0
}
var n = 0
var shouldBreak = false
let square1 = Square(up: 2, left: 1, down:4, right: 3, rotation: 0)
let square2 = Square(up: 1, left: 2, down:5, right: 4, rotation: 0)
let square3 = Square(up: 6, left: 3, down:2, right: 1, rotation: 0)
let square4 = Square(up: 1, left: 4, down:1, right: 5, rotation: 0)
let square5 = Square(up: 2, left: 6, down:5, right: 3, rotation: 0)
let square6 = Square(up: 6, left: 5, down:2, right: 5, rotation: 0)

var array: [Square] = [square1,square2,square3,square4,square5,square6]
var arrayPermutes: [[Square]] = []

func iterate() {
	if array[0].rotation < 3 {
		array[0].rotation += 1
	} else {
		var notFound: Bool = true
		for i in 1 ... 5 {
			if array[i].rotation < 3 {
				notFound = false
				array[i].rotation += 1
				for z in 0 ... i - 1 {
					array[z].rotation = 0
				}
				break
			}
		}
		if notFound {
			changePlaces()
		}
	}
}

func changePlaces() {
	if n < 719 {
		n += 1
		array.removeAll(keepingCapacity: true)
		for i in 0 ... 5 {
			array.append(arrayPermutes[n][i])
		}
		//array = arrayPermutes[n]
	} else {
		shouldBreak = true
	}
	print(n)
}

func swapper(_ a: [Square], _ b: Int, _ c: Int) -> [Square] {
	var a1 = a
	let d = a[b]
	a1[b] = a[c]
	a1[c] = d
	return a1
}

// Citation: https://stackoverflow.com/a/14444037

func permute(_ arr: [Square],_ k: Int) {
	var arr1 = arr
	for i in k ..< arr1.count {
		arr1 = swapper(arr, i, k)
		permute(arr1, k + 1);
		arr1 = swapper(arr, k, i)
	}
	if k == arr1.count - 1 {
		arrayPermutes.append(arr1)
	}
}
permute(array, 0)

func getRotatedSideColor(_ a: Square, _ b: Int) -> UInt8 {
	// 0 UP
	// 1 LEFT
	// 2 DOWN
	// 3 RIGHT
	let x = (b - a.rotation + 4) % 4
	
	if x == 0 {
		return a.up
	} else if x == 1 {
		return a.left
	} else if x == 2 {
		return a.down
	} else if x == 3 {
		return a.right
	} else {
		print(x)
		print("error!")
		return 0
	}
	// Rotation: CounterClockwise
}
var solutionArrays: [[Square]] = []
while !shouldBreak {
	if getRotatedSideColor(array[0], 3) == getRotatedSideColor(array[1], 1)
	&& getRotatedSideColor(array[1], 3) == getRotatedSideColor(array[2], 1)
	&& getRotatedSideColor(array[3], 3) == getRotatedSideColor(array[4], 1)
	&& getRotatedSideColor(array[4], 3) == getRotatedSideColor(array[5], 1)
	&& getRotatedSideColor(array[0], 2) == getRotatedSideColor(array[3], 0)
	&& getRotatedSideColor(array[1], 2) == getRotatedSideColor(array[4], 0)
	&& getRotatedSideColor(array[2], 2) == getRotatedSideColor(array[5], 0) {
		solutionArrays.append(array)
		print(array)
		for e in array {
			print(e)
		}
	}
	iterate()
}
//print(arrayPermutes)
print("The end!")

print(arrayPermutes.count)
print(solutionArrays)
print(solutionArrays.count)