1. UMass Lowell Computer Science 91.404 Analysis of Algorithms Prof. Karen Daniels Fall, 2001 Tuesday, 11/13/01 Data Structures Makeup Lecture Linked Lists & Trees

2. Linked Lists ä Types ä Singly vs. Doubly linked ä Pointer to Head and/or Tail ä NonCircular vs. Circular ä Type influences running time of operations 9 4 3 / head9 4 3 / head tail9 4 3 head

3. Doubly Linked List Operations source: 91.503 textbook Cormen et al.

4. Rooted Binary Tree Representation source: 91.503 textbook Cormen et al.

5. Multiple-Child Tree Representation source: 91.503 textbook Cormen et al.

6. Binary Tree Traversal ä “Visit” each node once  Running time in  (n) for an n-node binary tree ä Preorder: ABDCEF ä Visit node ä Visit left subtree ä Visit right subtree ä Inorder: DBAEFC ä Visit left subtree ä Visit node ä Visit right subtree ä Postorder: DBFECA ä Visit left subtree ä Visit right subtree ä Visit node B E C F D A

7. Binary Tree Traversal (continued) ä Preorder: ABDCEF ä Visit node ä Visit left subtree ä Visit right subtree B E C F D ATraversePreOrder(T) if T nil then return else Visit(T) TraversePreOrder(left[T]) TraversePreOrder(left[T]) TraversePreOrder(right[T]) TraversePreOrder(right[T])