module ChangeTests open FsUnit.Xunit open Xunit open Change [] let ``Change for 1 cent`` () = let coins = [1; 5; 10; 25] let target = 1 let expected = Some [1] findFewestCoins coins target |> should equal expected [] let ``Single coin change`` () = let coins = [1; 5; 10; 25; 100] let target = 25 let expected = Some [25] findFewestCoins coins target |> should equal expected [] let ``Multiple coin change`` () = let coins = [1; 5; 10; 25; 100] let target = 15 let expected = Some [5; 10] findFewestCoins coins target |> should equal expected [] let ``Change with Lilliputian Coins`` () = let coins = [1; 4; 15; 20; 50] let target = 23 let expected = Some [4; 4; 15] findFewestCoins coins target |> should equal expected [] let ``Change with Lower Elbonia Coins`` () = let coins = [1; 5; 10; 21; 25] let target = 63 let expected = Some [21; 21; 21] findFewestCoins coins target |> should equal expected [] let ``Large target values`` () = let coins = [1; 2; 5; 10; 20; 50; 100] let target = 999 let expected = Some [2; 2; 5; 20; 20; 50; 100; 100; 100; 100; 100; 100; 100; 100; 100] findFewestCoins coins target |> should equal expected [] let ``Possible change without unit coins available`` () = let coins = [2; 5; 10; 20; 50] let target = 21 let expected = Some [2; 2; 2; 5; 10] findFewestCoins coins target |> should equal expected [] let ``Another possible change without unit coins available`` () = let coins = [4; 5] let target = 27 let expected = Some [4; 4; 4; 5; 5; 5] findFewestCoins coins target |> should equal expected [] let ``A greedy approach is not optimal`` () = let coins = [1; 10; 11] let target = 20 let expected = Some [10; 10] findFewestCoins coins target |> should equal expected [] let ``No coins make 0 change`` () = let coins = [1; 5; 10; 21; 25] let target = 0 let expected: int list option = Some [] findFewestCoins coins target |> should equal expected [] let ``Error testing for change smaller than the smallest of coins`` () = let coins = [5; 10] let target = 3 let expected = None findFewestCoins coins target |> should equal expected [] let ``Error if no combination can add up to target`` () = let coins = [5; 10] let target = 94 let expected = None findFewestCoins coins target |> should equal expected [] let ``Cannot find negative change values`` () = let coins = [1; 2; 5] let target = -5 let expected = None findFewestCoins coins target |> should equal expected