module AlphameticsTests open FsUnit.Xunit open Xunit open Alphametics [] let ``Puzzle with three letters`` () = let puzzle = "I + BB == ILL" let expected = [ ('I', 1); ('B', 9); ('L', 0) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Solution must have unique value for each letter`` () = let puzzle = "A == B" let expected = None solve puzzle |> should equal expected [] let ``Leading zero solution is invalid`` () = let puzzle = "ACA + DD == BD" let expected = None solve puzzle |> should equal expected [] let ``Puzzle with two digits final carry`` () = let puzzle = "A + A + A + A + A + A + A + A + A + A + A + B == BCC" let expected = [ ('A', 9); ('B', 1); ('C', 0) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with four letters`` () = let puzzle = "AS + A == MOM" let expected = [ ('A', 9); ('S', 2); ('M', 1); ('O', 0) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with six letters`` () = let puzzle = "NO + NO + TOO == LATE" let expected = [ ('N', 7); ('O', 4); ('T', 9); ('L', 1); ('A', 0); ('E', 2) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with seven letters`` () = let puzzle = "HE + SEES + THE == LIGHT" let expected = [ ('E', 4); ('G', 2); ('H', 5); ('I', 0); ('L', 1); ('S', 9); ('T', 7) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with eight letters`` () = let puzzle = "SEND + MORE == MONEY" let expected = [ ('S', 9); ('E', 5); ('N', 6); ('D', 7); ('M', 1); ('O', 0); ('R', 8); ('Y', 2) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with ten letters`` () = let puzzle = "AND + A + STRONG + OFFENSE + AS + A + GOOD == DEFENSE" let expected = [ ('A', 5); ('D', 3); ('E', 4); ('F', 7); ('G', 8); ('N', 0); ('O', 2); ('R', 1); ('S', 6); ('T', 9) ] |> Map.ofList |> Some solve puzzle |> should equal expected [] let ``Puzzle with ten letters and 199 addends`` () = let puzzle = "THIS + A + FIRE + THEREFORE + FOR + ALL + HISTORIES + I + TELL + A + TALE + THAT + FALSIFIES + ITS + TITLE + TIS + A + LIE + THE + TALE + OF + THE + LAST + FIRE + HORSES + LATE + AFTER + THE + FIRST + FATHERS + FORESEE + THE + HORRORS + THE + LAST + FREE + TROLL + TERRIFIES + THE + HORSES + OF + FIRE + THE + TROLL + RESTS + AT + THE + HOLE + OF + LOSSES + IT + IS + THERE + THAT + SHE + STORES + ROLES + OF + LEATHERS + AFTER + SHE + SATISFIES + HER + HATE + OFF + THOSE + FEARS + A + TASTE + RISES + AS + SHE + HEARS + THE + LEAST + FAR + HORSE + THOSE + FAST + HORSES + THAT + FIRST + HEAR + THE + TROLL + FLEE + OFF + TO + THE + FOREST + THE + HORSES + THAT + ALERTS + RAISE + THE + STARES + OF + THE + OTHERS + AS + THE + TROLL + ASSAILS + AT + THE + TOTAL + SHIFT + HER + TEETH + TEAR + HOOF + OFF + TORSO + AS + THE + LAST + HORSE + FORFEITS + ITS + LIFE + THE + FIRST + FATHERS + HEAR + OF + THE + HORRORS + THEIR + FEARS + THAT + THE + FIRES + FOR + THEIR + FEASTS + ARREST + AS + THE + FIRST + FATHERS + RESETTLE + THE + LAST + OF + THE + FIRE + HORSES + THE + LAST + TROLL + HARASSES + THE + FOREST + HEART + FREE + AT + LAST + OF + THE + LAST + TROLL + ALL + OFFER + THEIR + FIRE + HEAT + TO + THE + ASSISTERS + FAR + OFF + THE + TROLL + FASTS + ITS + LIFE + SHORTER + AS + STARS + RISE + THE + HORSES + REST + SAFE + AFTER + ALL + SHARE + HOT + FISH + AS + THEIR + AFFILIATES + TAILOR + A + ROOFS + FOR + THEIR + SAFE == FORTRESSES" let expected = [ ('A', 1); ('E', 0); ('F', 5); ('H', 8); ('I', 7); ('L', 2); ('O', 6); ('R', 3); ('S', 4); ('T', 9) ] |> Map.ofList |> Some solve puzzle |> should equal expected