Add tasks for all the new languages

Task/Knapsack-problem-0-1/Ceylon/knapsack-problem-0-1-1.ceylon

@@ -0,0 +1,2 @@
+module knapsack "1.0.0" {
+}

Task/Knapsack-problem-0-1/Ceylon/knapsack-problem-0-1-2.ceylon

@@ -0,0 +1,82 @@
+shared void run() {
+    value knapsack = pack(items, empty(400));
+
+    print(knapsack);
+}
+
+class Item(name,weight,theValue) {
+    String name;
+    shared Integer weight;
+    shared Float theValue;
+
+    shared actual String string = "item(``name``, ``weight``, ``theValue``)";
+}
+
+class Knapsack(items,theValue,weight,available) {
+    shared Item[] items;
+    shared Float theValue;
+    shared Integer weight;
+    shared Integer available;
+
+    shared Boolean canAccept(Item item)
+        => item.weight <= available;
+
+    String itemsString = items.fold("")((total, remaining) => "``total``\t\n``remaining.string``" );
+
+    shared actual String string = "Total value: ``theValue``\nTotal weight: ``weight``\nItems:\n``itemsString``";
+}
+
+Knapsack empty(Integer capacity)
+    => Knapsack([], 0.0, 0, capacity);
+
+
+Item[] items =
+        [
+         Item("map", 9, 150.0),
+         Item("compass", 13, 35.0),
+         Item("water", 153, 200.0),
+         Item("sandwich", 50, 160.0),
+         Item("glucose", 15, 60.0),
+         Item("tin", 68, 45.0),
+         Item("banana", 27, 60.0),
+         Item("apple", 39, 40.0),
+         Item("cheese", 23, 30.0),
+         Item("beer", 52, 10.0),
+         Item("cream", 11, 70.0),
+         Item("camera", 32, 30.0),
+         Item("tshirt", 24, 15.0),
+         Item("trousers", 48, 10.0),
+         Item("umbrella", 73, 40.0),
+         Item("trousers", 42, 70.0),
+         Item("overclothes", 43, 75.0),
+         Item("notecase", 22, 80.0),
+         Item("sunglasses", 7, 20.0),
+         Item("towel", 18, 12.0),
+         Item("socks", 4, 50.0),
+         Item("book", 30, 10.0)
+        ];
+
+
+Knapsack add(Item item, Knapsack knapsack)
+    => Knapsack { items = knapsack.items.withTrailing(item);
+                  theValue = knapsack.theValue + item.theValue;
+                  weight = knapsack.weight + item.weight;
+                  available = knapsack.available - item.weight; };
+
+Float rating(Item item) => item.theValue / item.weight.float;
+
+Knapsack pack(Item[] items, Knapsack knapsack)
+    // Sort the items by decreasing rating, that is, value divided by weight
+    => let (itemsSorted =
+                items.group(rating)
+                     .sort(byDecreasing((Float->[Item+] entry) => entry.key))
+                     .map(Entry.item)
+                     .flatMap((element) => element)
+                     .sequence())
+
+    packRecursive(itemsSorted,knapsack);
+
+Knapsack packRecursive(Item[] sortedItems, Knapsack knapsack)
+    => if (exists firstItem=sortedItems.first, knapsack.canAccept(firstItem))
+        then packRecursive(sortedItems.rest, add(firstItem,knapsack))
+        else knapsack;