Improve and fix solver

2024-07-30 23:11:45 +02:00
parent a019ea406d
commit 3a2865f199
10 changed files with 334 additions and 92 deletions
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/Game.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/Game.kt
@@ -1,8 +1,45 @@
 package ch.dissem.yaep.domain

+import ch.dissem.yaep.domain.Animal.ANT
+import ch.dissem.yaep.domain.Animal.DOG
+import ch.dissem.yaep.domain.Animal.GOAT
+import ch.dissem.yaep.domain.Animal.SLOTH
+import ch.dissem.yaep.domain.Animal.SNAIL
+import ch.dissem.yaep.domain.Animal.ZEBRA
+import ch.dissem.yaep.domain.Dessert.CAKE
+import ch.dissem.yaep.domain.Dessert.CUPCAKE
+import ch.dissem.yaep.domain.Dessert.CUSTARD
+import ch.dissem.yaep.domain.Dessert.DOUGHNUT
+import ch.dissem.yaep.domain.Dessert.ICE_CREAM
+import ch.dissem.yaep.domain.Dessert.PIE
+import ch.dissem.yaep.domain.Drink.BEER
+import ch.dissem.yaep.domain.Drink.BEVERAGE
+import ch.dissem.yaep.domain.Drink.COFFEE
+import ch.dissem.yaep.domain.Drink.MILK
+import ch.dissem.yaep.domain.Drink.TEA
+import ch.dissem.yaep.domain.Drink.WINE
+import ch.dissem.yaep.domain.Fruit.BANANA
+import ch.dissem.yaep.domain.Fruit.GRAPES
+import ch.dissem.yaep.domain.Fruit.MANGO
+import ch.dissem.yaep.domain.Fruit.PEAR
+import ch.dissem.yaep.domain.Fruit.PINEAPPLE
+import ch.dissem.yaep.domain.Fruit.WATERMELON
+import ch.dissem.yaep.domain.Nationality.CANADA
+import ch.dissem.yaep.domain.Nationality.ENGLAND
+import ch.dissem.yaep.domain.Nationality.JAPAN
+import ch.dissem.yaep.domain.Nationality.SPAIN
+import ch.dissem.yaep.domain.Nationality.SWITZERLAND
+import ch.dissem.yaep.domain.Nationality.UKRAINE
+import ch.dissem.yaep.domain.Profession.ASTRONAUT
+import ch.dissem.yaep.domain.Profession.HEALTH_WORKER
+import ch.dissem.yaep.domain.Profession.ROCK_STAR
+import ch.dissem.yaep.domain.Profession.SCIENTIST
+import ch.dissem.yaep.domain.Profession.SOFTWARE_DEV
+import ch.dissem.yaep.domain.Profession.TEACHER
+
 class Game(
    val grid: Grid,
-    val clues: List<Clue>
+    val clues: Collection<Clue>
 ) {
    val horizontalClues = clues.filterIsInstance<HorizontalClue>()
    val verticalClues = clues.filterIsInstance<SameColumnClue<ItemClass<*>, ItemClass<*>>>()
@@ -29,9 +66,61 @@ class Game(

    fun isValid(): Boolean = areCategoriesValid() && clues.all { it.isValid(grid) }

-    fun isSolved(): Boolean = grid.cells.all { it.selection != null }
+    val isSolved: Boolean
+        get() = grid.rows.all { it.isSolved }

    override fun toString(): String {
        return grid.toString() + "\n\n" + clues.joinToString("\n* ", prefix = "* ")
    }
+
+    companion object {
+        fun parse(description: String): Game {
+            // TODO get options from string
+            val rowOptions = listOf<List<Item<*>>>(
+                listOf(
+                    HEALTH_WORKER,
+                    ROCK_STAR,
+                    SCIENTIST,
+                    SOFTWARE_DEV,
+                    ASTRONAUT,
+                    TEACHER
+                ).map { Item(it) },
+                listOf(ANT, DOG, GOAT, SLOTH, SNAIL, ZEBRA).map { Item(it) },
+                listOf(WATERMELON, MANGO, PEAR, GRAPES, PINEAPPLE, BANANA).map { Item(it) },
+                listOf(CUPCAKE, ICE_CREAM, DOUGHNUT, CAKE, PIE, CUSTARD).map { Item(it) },
+                listOf(SWITZERLAND, ENGLAND, JAPAN, UKRAINE, CANADA, SPAIN).map { Item(it) },
+                listOf(WINE, BEVERAGE, BEER, COFFEE, TEA, MILK).map { Item(it) }
+            )
+            val optionMap = rowOptions.flatten().associateBy(
+                keySelector = { it.itemType },
+                valueTransform = { it }
+            )
+            val clues: Collection<Clue> = description.lines()
+                .filter { it.startsWith("* ") }
+                .map { line ->
+                    Clue.parse(line) {
+                        optionMap[it] ?: throw IllegalArgumentException("Unknown option $it")
+                    }
+                }
+
+            return Game(
+                grid = Grid(
+                    rows = rowOptions
+                        .map { options -> createRow<ItemClass<*>>(options) }
+                        .toList()
+                ),
+                clues = clues
+            )
+        }
+
+        private fun <C : ItemClass<C>> createRow(options: List<Item<*>>): GameRow<*> {
+            @Suppress("UNCHECKED_CAST")
+            options as List<Item<C>>
+            return GameRow(
+                category = options.first().itemType.companion,
+                options = options,
+                cells = options.map { GameCell(options = options.toMutableList()) }
+            )
+        }
+    }
 }
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/GameCell.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/GameCell.kt
@@ -1,8 +1,8 @@
 package ch.dissem.yaep.domain

 class GameCell<C : ItemClass<C>>(
-    selection: Item<C>?,
-    val solution: Item<C>,
+    selection: Item<C>?=null,
+    val solution: Item<C>? = null,
    options: Collection<Item<C>>
 ) {
    val selectionChangedListeners = mutableListOf<(Item<C>?) -> Unit>()
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/GameRow.kt
@@ -5,52 +5,53 @@ class GameRow<C : ItemClass<C>>(
    val options: List<Item<C>>,
    val cells: List<GameCell<C>>
 ) : List<GameCell<C>> by cells {
+    var isSolved = false
+        private set
+
    fun indexOf(element: C) = indexOfFirst { it.selection?.itemType == element }

    fun cleanupOptions() {
-        cells.forEach {
-            cleanupOptions(it)
-        }
-//        do {
-//            var selectedSingleOption = false
-//            cells.forEach { cleanupOptions(it) }
-//            val selections = cells.mapNotNull { it.selection }
-//            options
-//                .filter { !selections.contains(it) }
-//                .forEach { option ->
-//                    if (cells.count { cell -> cell.options.contains(option) } == 1) {
-//                        cells
-//                            .filter { it.selection == null }
-//                            .first { cell -> cell.options.contains(option) }
-//                            .let { it.selection = option }
-//                        selectedSingleOption = true
-//                    }
-//                }
-//        } while (selectedSingleOption)
-    }
-
-    private fun cleanupOptions(cell: GameCell<C>, justSelected: Boolean = true) {
-        if ((justSelected && cell.selection != null) || (cell.options.size == 1 && cell.selection == null)) {
-            val selection = cell.selection
-            if (selection == null) {
-                cell.selection = cell.options.first()
-            } else {
-                cell.options.clear()
-                cell.options.add(selection)
+        if (
+            isSolved && all {
+                it.solution != null
+                        && it.options.size == 1
+                        && it.options.single() == it.selection
            }
-            filter { otherCell -> otherCell != cell && otherCell.hasNoSelection() }.forEach { otherCell ->
-                otherCell.options.remove(cell.selection)
-                cleanupOptions(otherCell, false)
+        ) return
+        do {
+            var changed = false
+            val selections = filter { it.selection != null }.let { cellsWithSelection ->
+                cellsWithSelection
+                    .filter { it.options.size != 1 }
+                    .forEach {
+                        it.options.clear()
+                        it.options.add(it.selection!!)
+                    }
+                cellsWithSelection.mapNotNull { it.selection }.toMutableSet()
            }
            filter { it.selection == null }
-                .flatMap { c -> c.options.map { o -> o to c } }
-                .groupBy { it.first }
-                .filter { it.value.size == 1 }
+                .forEach { it.options.removeAll(selections) }
+            filter { it.selection == null && it.options.size == 1 }
                .forEach {
-                    val c = it.value.single().second
-                    c.selection = it.key
-                    cleanupOptions(c, true)
+                    changed = true
+                    it.selection = it.options.single()
                }
+            if (!changed) {
+                filter { it.selection == null }
+                    .flatMap { c -> c.options.map { o -> o to c } }
+                    .groupBy { it.first }
+                    .filter { it.value.size == 1 }
+                    .forEach {
+                        val c = it.value.single().second
+                        c.selection = it.key
+                        changed = true
+                    }
+            }
+        } while (changed)
+        isSolved = all {
+            it.solution != null
+                    && it.options.size == 1
+                    && it.options.single() == it.selection
        }
    }

--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/clues.kt
@@ -7,6 +7,26 @@ sealed class Clue {
     * @return `true` if any option was removed
     */
    abstract fun removeForbiddenOptions(grid: Grid): Boolean
+
+    companion object {
+        fun <T : ItemClass<T>> parse(line: String, mapper: (ItemClass<*>) -> Item<T>): Clue {
+            return NeighbourClue.parse(line, mapper)
+                ?: OrderClue.parse(line, mapper)
+                ?: TripletClue.parse(line, mapper)
+                ?: SameColumnClue.parse(line, mapper)
+                ?: PositionClue.parse(line, mapper)
+                ?: throw IllegalStateException("Unknown clue: $line")
+        }
+    }
+}
+
+sealed interface ClueParser {
+    /**
+     * Parses a string description of a clue into a clue.
+     *
+     * Returns `null` if `line` isn't a representation of that clue.
+     */
+    fun <T : ItemClass<T>> parse(line: String, mapper: (ItemClass<*>) -> Item<T>): Clue?
 }

 sealed class HorizontalClue : Clue()
@@ -66,6 +86,21 @@ class NeighbourClue<A : ItemClass<A>, B : ItemClass<B>>(val a: Item<A>, val b: I
    }

    override fun toString() = "$aType is next to $bType"
+
+    companion object : ClueParser {
+        override fun <T : ItemClass<T>> parse(
+            line: String,
+            mapper: (ItemClass<*>) -> Item<T>
+        ): Clue? {
+            val regex = Regex("^(\\* )?(?<a>[A-Z_]+) is next to (?<b>[A-Z_]+)$")
+            val matchResult = regex.matchEntire(line) ?: return null
+
+            val a = ItemClass.parse(matchResult.groups["a"]!!.value)
+            val b = ItemClass.parse(matchResult.groups["b"]!!.value)
+
+            return NeighbourClue(mapper(a), mapper(b))
+        }
+    }
 }

 class OrderClue<L : ItemClass<L>, R : ItemClass<R>>(val left: Item<L>, val right: Item<R>) :
@@ -113,6 +148,21 @@ class OrderClue<L : ItemClass<L>, R : ItemClass<R>>(val left: Item<L>, val right
    }

    override fun toString() = "$leftType is left of $rightType"
+
+    companion object : ClueParser {
+        override fun <T : ItemClass<T>> parse(
+            line: String,
+            mapper: (ItemClass<*>) -> Item<T>
+        ): Clue? {
+            val regex = Regex("^(\\* )?(?<left>[A-Z_]+) is left of (?<right>[A-Z_]+)$")
+            val matchResult = regex.matchEntire(line) ?: return null
+
+            val left = ItemClass.parse(matchResult.groups["left"]!!.value)
+            val right = ItemClass.parse(matchResult.groups["right"]!!.value)
+
+            return OrderClue(mapper(left), mapper(right))
+        }
+    }
 }

 class TripletClue<A : ItemClass<A>, B : ItemClass<B>, C : ItemClass<C>>(
@@ -242,6 +292,23 @@ class TripletClue<A : ItemClass<A>, B : ItemClass<B>, C : ItemClass<C>>(

    override fun toString(): String =
        "$bType is between the neighbours $aType and $cType to both sides"
+
+    companion object : ClueParser {
+        override fun <T : ItemClass<T>> parse(
+            line: String,
+            mapper: (ItemClass<*>) -> Item<T>
+        ): Clue? {
+            val regex =
+                Regex("^(\\* )?(?<b>[A-Z_]+) is between the neighbours (?<a>[A-Z_]+) and (?<c>[A-Z_]+) to both sides$")
+            val matchResult = regex.matchEntire(line) ?: return null
+
+            val a = ItemClass.parse(matchResult.groups["a"]!!.value)
+            val b = ItemClass.parse(matchResult.groups["b"]!!.value)
+            val c = ItemClass.parse(matchResult.groups["c"]!!.value)
+
+            return TripletClue(mapper(a), mapper(b), mapper(c))
+        }
+    }
 }

 class SameColumnClue<A : ItemClass<A>, B : ItemClass<B>>(val a: Item<A>, val b: Item<B>) : Clue() {
@@ -291,6 +358,22 @@ class SameColumnClue<A : ItemClass<A>, B : ItemClass<B>>(val a: Item<A>, val b:
    }

    override fun toString(): String = "$aType and $bType are in the same column"
+
+    companion object : ClueParser {
+        override fun <T : ItemClass<T>> parse(
+            line: String,
+            mapper: (ItemClass<*>) -> Item<T>
+        ): Clue? {
+            val regex = Regex("^(\\* )?(?<a>[A-Z_]+) and (?<b>[A-Z_]+) are in the same column$")
+            val matchResult = regex.matchEntire(line) ?: return null
+
+            val a = ItemClass.parse(matchResult.groups["a"]!!.value)
+            val b = ItemClass.parse(matchResult.groups["b"]!!.value)
+
+            return SameColumnClue(mapper(a), mapper(b))
+        }
+    }
+
 }

 class PositionClue<C : ItemClass<C>>(val item: Item<C>, val index: Int) : Clue() {
@@ -307,14 +390,31 @@ class PositionClue<C : ItemClass<C>>(val item: Item<C>, val index: Int) : Clue()
        val row = grid[itemType.companion]
        var removed = false
        row.forEachIndexed { i, cell ->
-            if (i == index) {
-                removed = cell.options.retainAll { it == item } || removed
-            } else {
-                removed = cell.options.remove(item) || removed
+            if (cell.hasNoSelection()) {
+                removed = if (i == index) {
+                    cell.options.retainAll { it == item } || removed
+                } else {
+                    cell.options.remove(item) || removed
+                }
            }
        }
        return removed
    }

    override fun toString() = "$itemType is at position $index"
+
+    companion object : ClueParser {
+        override fun <T : ItemClass<T>> parse(
+            line: String,
+            mapper: (ItemClass<*>) -> Item<T>
+        ): Clue? {
+            val regex = Regex("^(\\* )?(?<type>[A-Z_]+) is at position (?<pos>\\d)$")
+            val matchResult = regex.matchEntire(line) ?: return null
+
+            val type = ItemClass.parse(matchResult.groups["type"]!!.value)
+            val pos = matchResult.groups["pos"]!!.value.toInt()
+
+            return PositionClue(mapper(type), pos)
+        }
+    }
 }
--- a/domain/src/main/kotlin/ch/dissem/yaep/domain/items.kt
+++ b/domain/src/main/kotlin/ch/dissem/yaep/domain/items.kt
@@ -152,6 +152,8 @@ private fun idic(symbol: String): Array<String> = Array(GENDERS.size * SKIN_TONE
 sealed interface ItemClass<out SELF : ItemClass<SELF>> {
    val symbols: Array<String>

+    val name: String
+
    val companion: ItemClassCompanion<SELF>

    companion object {
@@ -168,6 +170,10 @@ sealed interface ItemClass<out SELF : ItemClass<SELF>> {
        fun randomClasses(n: Int): List<ItemClassCompanion<*>> {
            return classes.shuffled().take(n)
        }
+
+        fun parse(name: String): ItemClass<*> {
+            return classes.mapNotNull { it.parse(name) }.single()
+        }
    }
 }

@@ -177,4 +183,8 @@ sealed interface ItemClassCompanion<out C : ItemClass<C>> {
    fun randomItems(n: Int): List<C> {
        return items.shuffled().take(n)
    }
+
+    fun parse(name: String): C? {
+        return items.firstOrNull { it.name == name }
+    }
 }
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/GameTest.kt
@@ -30,7 +30,11 @@ class GameTest {
                game = generateGame()
            }
            println("Generated game #$i in ${time.inWholeMilliseconds}ms")
-            expect(solve(game.grid, game.clues)).toEqual(SOLVABLE)
+            val solvable = solve(game.grid, game.clues)
+            if (solvable != SOLVABLE) {
+                println("Puzzle:\n$game")
+            }
+            expect(solvable).toEqual(SOLVABLE)
            expect(time).toBeLessThan(500.milliseconds)
            if (time < fastest) {
                fastest = time
@@ -67,8 +71,8 @@ class GameTest {
            feature(Game::areCategoriesValid).toEqual(true)
            feature(Game::isValid).toEqual(true)
            feature(Game::clues) {
-                feature(List<Clue>::size).toBeGreaterThan(5)
-                feature(List<Clue>::size).toBeLessThan(30)
+                feature(Collection<Clue>::size).toBeGreaterThan(5)
+                feature(Collection<Clue>::size).toBeLessThan(30)
            }
        }
        println("Clues: ${game.clues.size}")
@@ -124,4 +128,42 @@ class GameTest {
        expect(solve(game.grid, game.clues)).toEqual(SOLVABLE)
    }

+    @Test
+    fun `ensure specific game is solvable`() {
+        val game = Game.parse("""
+            👩🏿‍⚕️👨🏽‍🎤👩🏿‍⚕️  👩🏾‍🚀🧑🏿‍🏫
+            🐜🐕  🐐  🐐
+            🍉🥭🍐🍇🍍  
+            🧁🍨🍩🍰🥧  
+            🇨🇭🇬🇧🇯🇵🇺🇦🇬🇧🇨🇦
+            🍷🧃🍺🧃    
+
+            * ZEBRA is between the neighbours PIE and PEAR to both sides
+            * WINE is at position 0
+            * SLOTH is between the neighbours ZEBRA and COFFEE to both sides
+            * ICE_CREAM is left of MANGO
+            * SWITZERLAND is at position 0
+            * PIE is at position 4
+            * SCIENTIST is between the neighbours ASTRONAUT and PEAR to both sides
+            * ROCK_STAR is between the neighbours SNAIL and ANT to both sides
+            * SNAIL is between the neighbours ROCK_STAR and TEA to both sides
+            * SOFTWARE_DEV is left of SLOTH
+            * SOFTWARE_DEV is left of HEALTH_WORKER
+            * MILK is between the neighbours CUSTARD and ZEBRA to both sides
+            * SLOTH is between the neighbours CUSTARD and CAKE to both sides
+            * SPAIN is between the neighbours CUSTARD and GRAPES to both sides
+            * SCIENTIST is between the neighbours SNAIL and SLOTH to both sides
+            * DOG is between the neighbours CUPCAKE and BEER to both sides
+            * SNAIL is between the neighbours BANANA and GRAPES to both sides
+            * SLOTH is between the neighbours GRAPES and CANADA to both sides
+            * UKRAINE and SCIENTIST are in the same column
+            * DOG is between the neighbours JAPAN and SWITZERLAND to both sides
+            * SLOTH is between the neighbours GOAT and TEA to both sides
+            * ROCK_STAR and ENGLAND are in the same column
+            * ROCK_STAR is next to DOUGHNUT
+            * PINEAPPLE is between the neighbours TEACHER and GRAPES to both sides
+        """.trimIndent())
+
+        expect(solve(game.grid, game.clues)).toEqual(SOLVABLE)
+    }
 }
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/NeighbourClueTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/NeighbourClueTest.kt
@@ -15,8 +15,8 @@ class NeighbourClueTest : ClueTest() {
                    val a = grid[ia][j - 1]
                    val b = grid[ib][j]

-                    expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(true)
-                    expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(true)
                }
            }
        }
@@ -35,8 +35,8 @@ class NeighbourClueTest : ClueTest() {
                        val a = grid[ia][ja]
                        val b = grid[ib][jb]

-                        expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(false)
-                        expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+                        expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(false)
+                        expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
                    }
                }
            }
@@ -58,32 +58,32 @@ class NeighbourClueTest : ClueTest() {
                    rowB.forEach { it.selection = null; it.options.clear() }

                    a.selection = null
-                    a.options.add(a.solution)
+                    a.options.add(a.solution!!)
                    b.selection = b.solution
                    b.options.clear()

-                    expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(true)
-                    expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(true)

                    a.selection = a.solution
                    a.options.clear()
                    b.selection = null
-                    b.options.add(b.solution)
+                    b.options.add(b.solution!!)

-                    expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(true)
-                    expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
+                    expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(true)

                    if (j < size - 1) {
                        val notA = rowA[j + 1]

                        a.selection = null
                        a.options.clear()
-                        notA.options.add(a.solution)
+                        notA.options.add(a.solution!!)
                        b.selection = b.solution
                        b.options.clear()

-                        expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(true)
-                        expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(true)
+                        expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
+                        expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(true)
                    }
                }
            }
@@ -102,8 +102,8 @@ class NeighbourClueTest : ClueTest() {

        rowB[3].selection = b.solution

-        expect(NeighbourClue(a.solution, b.solution).isValid(grid)).toEqual(false)
-        expect(NeighbourClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+        expect(NeighbourClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(false)
+        expect(NeighbourClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
    }

 }
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/OrderClueTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/OrderClueTest.kt
@@ -16,7 +16,7 @@ class OrderClueTest : ClueTest() {
                            val a = grid[ia][ja]
                            val b = grid[ib][jb]

-                            expect(OrderClue(a.solution, b.solution).isValid(grid)).toEqual(true)
+                            expect(OrderClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
                        }
                    }
                }
@@ -35,7 +35,7 @@ class OrderClueTest : ClueTest() {
                            val a = grid[ia][ja]
                            val b = grid[ib][jb]

-                            expect(OrderClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+                            expect(OrderClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
                        }
                    }
                }
@@ -49,7 +49,7 @@ class OrderClueTest : ClueTest() {
        for (rowA in grid.rows) {
            for (rowB in grid.rows) {
                for (i in 0 until size) {
-                    expect(OrderClue(rowA[i].solution, rowB[i].solution).isValid(grid)).toEqual(false)
+                    expect(OrderClue(rowA[i].solution!!, rowB[i].solution!!).isValid(grid)).toEqual(false)
                }
            }
        }
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/SameColumnClueTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/SameColumnClueTest.kt
@@ -14,8 +14,8 @@ class SameColumnClueTest : ClueTest() {
                    val a = grid[ia][j]
                    val b = grid[ib][j]

-                    expect(SameColumnClue(a.solution, b.solution).isValid(grid)).toEqual(true)
-                    expect(SameColumnClue(b.solution, a.solution).isValid(grid)).toEqual(true)
+                    expect(SameColumnClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(true)
+                    expect(SameColumnClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(true)
                }
            }
        }
@@ -32,8 +32,8 @@ class SameColumnClueTest : ClueTest() {
                        val a = grid[ia][ja]
                        val b = grid[ib][jb]

-                        expect(SameColumnClue(a.solution, b.solution).isValid(grid)).toEqual(false)
-                        expect(SameColumnClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+                        expect(SameColumnClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(false)
+                        expect(SameColumnClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
                    }
                }
            }
@@ -54,8 +54,8 @@ class SameColumnClueTest : ClueTest() {
                        a.selection = a.solution
                        b.selection = b.solution

-                        expect(SameColumnClue(a.solution, b.solution).isValid(grid)).toEqual(false)
-                        expect(SameColumnClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+                        expect(SameColumnClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(false)
+                        expect(SameColumnClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
                    }
                }
            }
@@ -87,8 +87,8 @@ class SameColumnClueTest : ClueTest() {
                }
            }

-            expect(SameColumnClue(a.solution, b.solution).isValid(grid)).toEqual(false)
-            expect(SameColumnClue(b.solution, a.solution).isValid(grid)).toEqual(false)
+            expect(SameColumnClue(a.solution!!, b.solution!!).isValid(grid)).toEqual(false)
+            expect(SameColumnClue(b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
        }
    }
 }
--- a/domain/src/test/kotlin/ch/dissem/yaep/domain/TripletClueTest.kt
+++ b/domain/src/test/kotlin/ch/dissem/yaep/domain/TripletClueTest.kt
@@ -17,8 +17,8 @@ class TripletClueTest : ClueTest() {
                        val b = grid[ib][j - 1]
                        val c = grid[ic][j]

-                        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(true)
-                        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(true)
+                        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(true)
+                        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(true)
                    }
                }
            }
@@ -38,14 +38,14 @@ class TripletClueTest : ClueTest() {

        rowB[0].selection = b.solution

-        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(false)
-        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(false)
+        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(false)
+        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(false)

        rowB[0].selection = null
        rowB[grid.size - 1].selection = b.solution

-        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(false)
-        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(false)
+        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(false)
+        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
    }

    @Test
@@ -61,10 +61,10 @@ class TripletClueTest : ClueTest() {
        val rowC = grid[1]
        val c = rowC[ic]

-        val clue = TripletClue(a.solution, b.solution, c.solution)
+        val clue = TripletClue(a.solution!!, b.solution!!, c.solution!!)

        b.selection = b.solution
-        c.options.add(c.solution)
+        c.options.add(c.solution!!)


        rowA.forEachIndexed { index, notA ->
@@ -75,7 +75,7 @@ class TripletClueTest : ClueTest() {
                }

                index == ic -> {
-                    rowC[ia].options.add(c.solution)
+                    rowC[ia].options.add(c.solution!!)
                    expect(clue.isValid(grid)).toEqual(true)
                }

@@ -97,8 +97,8 @@ class TripletClueTest : ClueTest() {
        a.selection = a.solution
        grid[1][4].selection = c.solution

-        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(false)
-        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(false)
+        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(false)
+        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
    }

    @Test
@@ -115,11 +115,11 @@ class TripletClueTest : ClueTest() {
        b.options.clear()
        c.options.clear()

-        rowB[4].options.add(b.solution)
-        rowC[5].options.add(c.solution)
+        rowB[4].options.add(b.solution!!)
+        rowC[5].options.add(c.solution!!)

-        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(true)
-        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(true)
+        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(true)
+        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(true)
    }

    @Test
@@ -136,7 +136,7 @@ class TripletClueTest : ClueTest() {
        rowB[4].selection = rowC[3].solution
        c.selection = rowC[3].solution

-        expect(TripletClue(a.solution, b.solution, c.solution).isValid(grid)).toEqual(false)
-        expect(TripletClue(c.solution, b.solution, a.solution).isValid(grid)).toEqual(false)
+        expect(TripletClue(a.solution!!, b.solution!!, c.solution!!).isValid(grid)).toEqual(false)
+        expect(TripletClue(c.solution!!, b.solution!!, a.solution!!).isValid(grid)).toEqual(false)
    }
 }