View difference between Paste ID: qwmzXKF7 and vdjWmTq3

-let rec sumListBy selector xs =
+let rec sumListBy money coins highestCoinUsed xs =
     match xs with
-    | x::xs -> selector x + sumListBy selector xs
+    | x::xs -> countChangeImpl (money - x) coins (max x highestCoinUsed) + sumListBy money coins highestCoinUsed xs
     | [] -> 0
 and filterList highestCoinUsed xs ys =
-let rec filterListImpl predicate xs ys =
+
     | x::xs when x >= highestCoinUsed -> filterList highestCoinUsed xs (x::ys)
-    | x::xs when predicate x -> filterListImpl predicate xs (x::ys)
+    | _::xs -> filterList highestCoinUsed xs ys
-    | _::xs -> filterListImpl predicate xs ys
+
 and countChangeImpl (money: int) (coins: int list) (highestCoinUsed: int) =
     match money with
-let filterList predicate xs = filterListImpl predicate xs []
+
     | money when money < 0 -> 0
-let rec countChangeImpl (money: int) (coins: int list) (highestCoinUsed: int) =
+
         let usableCoins = filterList highestCoinUsed coins []
         sumListBy money coins highestCoinUsed usableCoins
 
 let countChange money coins = countChangeImpl money coins 0
-        let usableCoins = filterList (fun coin -> coin >= highestCoinUsed) coins
+
-        sumListBy (fun coin -> countChangeImpl (money - coin) coins (max coin highestCoinUsed)) usableCoins
+
     let actual = countChange money coins
     printf "money = %d; coins = %A; expected %d; actual %d\n" money coins expected actual
 
 [<EntryPoint>]
 let main argv =
     countChangeTest 301 [5;10;20;50;100;200;500] 0
     countChangeTest 300 [500;5;50;100;20;200;10] 1022
     countChangeTest 30 [10;20;100;50;5] 6
     countChangeTest 4 [1;2] 3
     System.Console.ReadLine() |> ignore
     0