9/26/2018 Data Structure & Algorithm. Assignment04: 3 parts Quiz: recursion, insertionsort, trees Basic concept: Linked-List Priority queues Heaps

Transcription

1 9/26/2018 Data Structure & Algorithm Assignment04: 3 parts Quiz: recursion, insertionsort, trees Basic concept: Linked-List Priority queues Heaps 1

2 Quiz 10 points (as stated in the first class meeting) Wednesday, Oct. 3, closed-book 30 min Test: all the content in the previous classes (Sept. 5 Oct. 1) all the assignments from assignment01 assignment04 2

3 Assignment 01 (points: 0.5) due Oct. 1, noon Implement postorder in Tree1.java file Instruction: Don t change anything in Tree1.java except filling the method postorder (you can add new methods) Hint: read the preorder method in the same file. 3

4 Assignment 01 (points: 0.5) due Oct. 1, noon Grading: If the algorithm is correct (the same as the algorithm described in the book, page 335) and the output is correct, you get the full points: 0.5 Correct sequence order is: Visit B, Visit C, Visit D, Visit G, Visit H, Visit E, Visit I, Visit J, Visit K, Visit F, Visit A Otherwise, you get 0. 4

5 Assignment 02 (points: 1) due Oct. 1, noon Implement pathlength in Tree2.java file Instruction: Don t change anything in Tree2.java except filling the method pathlength (you can add new methods) 5

6 Assignment 02 (points: 1) due Oct. 1, noon Implement pathlength in Tree2.java file Instruction: Don t change anything in Tree2.java except filling the method pathlength (you can add new methods) Hint: 1. visit all the nodes, 2. when visit a node, compute the depth of the node, 3. sum all the depths of the node 6

7 Assignment 02 (points: 1) due Oct. 1, noon The path length of this tree is 15. 7

8 Assignment 02 (points: 1) due Oct. 1, noon Grading: If the algorithm is correct and the output is correct, you get the full points: 1 Correct output: the tree s path length is: 15 Otherwise, you get 0. 8

9 Assignment 03 (points: 1.5) due Oct. 1, noon Implement calculate in BinaryTree.java file Instruction: Don t change anything in BinaryTree.java except filling the method calculate (you can add new methods) 9

10 Assignment 03 (points: 1.5) due Oct. 1, noon Correct output is: the calculation result is:

11 Assignment 03 (points: 1.5) due Oct. 1, noon Visit each node: 1. if the node is internal, do if the node is external, do... (you should use a recursive method, similar to the traversal algorithms) 11

12 Assignment 03 (points: 1.5) due Oct. 1, noon Grading: If the algorithm is correct and the output is correct, you get the full points: 1.5 Correct output: the calcualtion result is: -13 Otherwise, you get 0. 12

13 9/26/2018 Data Structure & Algorithm Assignment04: 3 parts Quiz: recursion, insertionsort, trees Basic concept: Linked-List Priority queues Heaps 13

14 Recursion Call -> Push Return -> Pop 14

15 Quiz question example: recursion 15

16 Quiz question example: InsertionSort 16

17 Quiz question example: Trees Define tree recursively: A tree T is either empty or consists of a node r, called the root of T, and a (possibly empty) set of subtrees whose roots are the children of r. 17

18 Trees 18

19 9/26/2018 Data Structure & Algorithm Assignment04: 3 parts Quiz: recursion, insertionsort, trees Basic concept: Linked-List Priority queues Heaps 19

20 Linked List I didn t want to discuss linked lists in the class... Here s why 20

21 Linked List I am going to introduce linked lists (and put a question in this coming quiz)... Here s why 21

22 Linked list: a collection of nodes 22

23 Linked list: linked 23

24 Linked list: Node Element Next 24

25 Linked list: Singly Linked List Element Next 25

26 Linked list: Head and Tail NULL Element Next 1. Head 2. Tail 3. Size 26

27 Singly Linked List Implementation - Node instance variables: element, next constructor: Node(E e, Node<E> n) public methods: E getelement() Node<E> getnext() void setnext(node<e> n) 27

28 Singly Linked List Implementation: List instance variable: head, tail, size constructor: SinglyLinkedList() public methods: int size() boolean isempty() E first() E last() void addfrist() void addlast() E removefirst() 28

29 Singly Linked List Implementation: List instance variable: head, tail, size constructor: SinglyLinkedList() public methods: int size() boolean isempty() E first() E last() void addfrist() void addlast() E removefirst() Can we do removelast()? 29

30 Make SinglyLinkedList implements Iterable 30

31 Make SinglyLinkedList implements Iterable 31

32 Make SinglyLinkedList implements Iterable 32