Completed Positional List from Book.

Author: MayankShah1

.idea/workspace.xml

@@ -0,0 +1,35 @@
+import favourites_sorted_list as FL
+
+class FavouritesListMTF(FL.FavouritesList):
+    """List of elements ordered with move-to-front heuristic"""
+
+    # override _move_up to provide move-to-front semantics
+    def _move_up(self, p):
+        """Move accessed item at Position p to front of list"""
+        if p != self._data.first():
+            self._data.add_first(self._data.delete(p))
+
+    # override top because list is no longer sorted
+    def top(self, k):
+        """Generate sequence of top k elements in term of access count."""
+        if not 1 <= k <= len(self):
+            raise ValueError('Illegal value for k')
+
+        # we begin by making the copy of the original list
+        temp = FL.PositionalList()
+        for item in self._data:
+            temp.add_last(item)
+
+        # we repeatedly find, report, and remove the element with largest count
+        for j in range(k):
+            # find and report next highest from temp
+            highPos = temp.first()
+            walk = temp.after(highPos)
+            while walk is not None:
+                if walk.element()._count > highPos.element._count:
+                    highPos = walk
+                walk = temp.after(walk)
+            # we have found the element with highest count
+            yield highPos.element()._value
+            temp.delete(highPos)
+