Linear List Teknik Informatika Universitas Muhammadiyah Malang SP - 2013 Algoritma & Struktur Data.

Presentasi berjudul: "Linear List Teknik Informatika Universitas Muhammadiyah Malang SP - 2013 Algoritma & Struktur Data."— Transcript presentasi:

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2 Linear List Teknik Informatika Universitas Muhammadiyah Malang SP - 2013 Algoritma & Struktur Data

3 Representasi Linear List dengan Array dan Linked list

4 Tujuan Instruksional Mahasiswa mampu : Memahami struktur data dari linear list Mampu merepresentasikan linear list menggunakan array dan linked list Mengimplementasikan linear list ke dalam program

5 Struktur Data Struktur data terdiri dari obyek data dan operasi-operasi. Obyek data adalah sekumpulan instance (model/sampling) Contoh obyek data : integer = {0, +1, -1, +2, -2, +3, -3, …} daysOfWeek = {S,M,T,W,Th,F,Sa} myDataObject = {apple, chair, 2, 5.2, red, green, Jack}

6 Struktur Data Struktur data dibedakan menjadi 2 jenis : 1.Linear list direpresentasikan dengan : array dan linked list 2.Struktur data hirarki Direpresentasikan dengan : tree dan graph

7 Linear Lists Disebut juga dengan ordered list. Bentuk instance dari linear list : (e 0, e 1, e 2, …, e n-1 ) where e i denotes a list element n >= 0 is finite (list size is n)

8 Linear Lists L = (e 0, e 1, e 2, e 3, …, e n-1 ) relationships e 0 is the zero’th (or front) element e n-1 is the last element e i immediately precedes e i+1

9 Linear List Examples/Instances Students in COP3530 = (Jack, Jill, Abe, Henry, Mary, …, Judy) Exams in COP3530 = (exam1, exam2, exam3) Days of Week = (S, M, T, W, Th, F, Sa) Months = (Jan, Feb, Mar, Apr, …, Nov, Dec)

10 Struktur data Operations Operasi : aksi yang dapat dilakukan pada obyek data. Operasi-operasi yang umum pada obyek data : penambahan elemen, penghapusan elemen, pengaksesan elemen, dll.

11 Linear List Operations— size() determine list size L = (a,b,c,d,e) size = 5

12 Linear List Operations— get(theIndex) get element with given index L = (a,b,c,d,e) get(0) = a get(2) = c get(4) = e get(-1) = error get(9) = error

13 Linear List Operations— indexOf(theElement) determine the index of an element L = (a,b,d,b,a) indexOf(d) = 2 indexOf(a) = 0 indexOf(z) = -1

14 Linear List Operations— remove(theIndex) remove and return element with given index L = (a,b,c,d,e,f,g) remove(2) returns c and L becomes (a,b,d,e,f,g) index of d,e,f, and g decrease by 1

15 Linear List Operations— remove(theIndex) remove and return element with given index L = (a,b,c,d,e,f,g) remove(-1) => error remove(20) => error

16 Linear List Operations— add(theIndex, theElement) add an element so that the new element has a specified index L = (a,b,c,d,e,f,g) add(0,h) => L = (h,a,b,c,d,e,f,g) index of a,b,c,d,e,f, and g increase by 1

17 Linear List Operations— add(theIndex, theElement) L = (a,b,c,d,e,f,g) add(2,h) => L = (a,b,h,c,d,e,f,g) index of c,d,e,f, and g increase by 1 add(10,h) => error add(-6,h) => error

18 Latihan Diketahui L=(a,b,c,d). L adalah sebuah array linier list. Tentukan hasil yang didapatkan ketika dilakukan perintah berikut ini : a)isEmpty() b)size() c)get(0), get(2),get(6),get(-3) d)indexOf(a), indexOf(c), indexOf(q) e)remove(0), remove(2), remove(3) f)add(0,e), add(2,f), add(3,g), add(4,h), add(6,h), add(-3,h)

19 Data Structure Specification  Language independent  Abstract Data Type  Java  Interface  Abstract Class

20 Linear List Abstract Data Type AbstractDataType LinearList { instances ordered finite collections of zero or more elements operations isEmpty(): return true if the list is empty, false otherwise size(): return the list size (i.e., number of elements in the list) get(index): return the indexth element of the list indexO f(x): return the index of the first occurrence of x in the list, return -1 if x is not in the list remove(index): remove and return the indexth element, elements with higher index have their index reduced by 1 add(theIndex, x): insert x as the indexth element, elements with theIndex >= index have their index increased by 1 output(): output the list elements from left to right }

21 Linear List as Java Interface An interface may include constants and abstract methods (i.e., methods for which no implementation is provided).

22 Linear List as Java Interface public interface LinearList { public boolean isEmpty(); public int size(); public Object get(int index); public int indexOf(Object elem); public Object remove(int index); public void add(int index, Object obj); public String toString(); }

23 Implementing An Interface public class ArrayLinearList implements LinearList { // code for all LinearList methods must be provided here }

24 Linear List As An Abstract Class An abstract class may include constants, variables, abstract methods, and nonabstract methods.

25 Linear List As Java Abstract Class public abstract class LinearListAsAbstractClass { public abstract boolean isEmpty(); public abstract int size(); public abstract Object get(int index); public abstract int indexOf(Object theElement); public abstract Object remove(int index); public abstract void add(int index, Object theElement); public abstract String toString(); }

26 Extending A Java Class public class ArrayLinearList extends LinearListAsAbstractClass { // code for all abstract classes must come here }

27 0123456 Linear List Array Representation use a one-dimensional array element[] abcde L = (a, b, c, d, e) Store element i of list in element[i].

28 Representation Used In Text put element i of list in element[i] use a variable size to record current number of elements 0123456 abcde size = 5

29 Add/Remove An Element abcde size = 5 agbcde size = 6 add(1,g)

30 Data Type Of Array element[] Data type of list elements is unknown. Define element[] to be of data type Object. Cannot put elements of primitive data types (int, float, double, char, etc.) into our linear lists.

31 Increasing Array Length Length of array element[] is 6. abcdef newArray = new Object[15]; First create a new and larger array

32 Increasing Array Length Now copy elements from old array to new one. abcdefabcdef

33 Increasing Array Length Finally, rename new array. element = newArray; element.length = 15 abcdef element[0]

34 Class ArrayLinearList Merupakan hasil implements dari interface LinearList.

35 Create An Empty List ArrayLinearList a = new ArrayLinearList(100), b = new ArrayLinearList(), c; LinearList d = new ArrayLinearList(1000), e = new ArrayLinearList(), f;

36 Using A Linear List System.out.println(a.size()); a.add(0, new Integer(2)); b.add(0, new Integer(4)); System.out.println(a); b.remove(0); if (a.isEmpty()) a.add(0, new Integer(5));

37 Array Of Linear Lists LinearList [] x = new LinearList [4]; x[0] = new ArrayLinearList(20); x[1] = new Chain(); x[2] = new Chain(); x[3] = new ArrayLinearList(); for (int i = 0; i < 4; i++) x[i].add(0, new Integer(i));

38 The Class ArrayLinearList /** array implementation of LinearList */ package dataStructures; import java.util.*; // has Iterator interface import utilities.*; // has array resizing class public class ArrayLinearList implements LinearList { // data members protected Object [] element; // array of elements protected int size; // number of elements in array // constructors and other methods come here }

39 A Constructor /** create a list with initial capacity initialCapacity * @throws IllegalArgumentException when * initialCapacity < 1 */ public ArrayLinearList(int initialCapacity) { if (initialCapacity < 1) throw new IllegalArgumentException ("initialCapacity must be >= 1"); // size has the default initial value of 0 element = new Object [initialCapacity]; }

40 Another Constructor /** create a list with initial capacity 10 */ public ArrayLinearList() {// use default capacity of 10 this(10); }

41 The Method isEmpty /** @return true iff list is empty */ public boolean isEmpty() {return size == 0;}

42 The Method size() /** @return current number of elements in list */ public int size() {return size;}

43 The Method checkIndex /** @throws IndexOutOfBoundsException when * index is not between 0 and size - 1 */ void checkIndex(int index) { if (index = size) throw new IndexOutOfBoundsException ("index = " + index + " size = " + size); }

44 The Method get /** @return element with specified index * @throws IndexOutOfBoundsException when * index is not between 0 and size - 1 */ public Object get(int index) { checkIndex(index); return element[index]; }

45 The Method indexOf /** @return index of first occurrence of theElement, * return -1 if theElement not in list */ public int indexOf(Object theElement) { // search element[] for theElement for (int i = 0; i < size; i++) if (element[i].equals(theElement)) return i; // theElement not found return -1; }

46 The Method remove public Object remove(int index) { checkIndex(index); // valid index, shift elements with higher index Object removedElement = element[index]; for (int i = index + 1; i < size; i++) element[i-1] = element[i]; element[--size] = null; // enable garbage collection return removedElement; }

47 The Method add public void add(int index, Object theElement) { if (index size) // invalid list position throw new IndexOutOfBoundsException ("index = " + index + " size = " + size); // valid index, make sure we have space if (size == element.length) // no space, double capacity element = ChangeArrayLength.changeLength1D(element, 2 * size);

48 The Method add // shift elements right one position for (int i = size - 1; i >= index; i--) element[i + 1] = element[i]; element[index] = theElement; size++; }

49 Faster Way To Shift Elements 1 Right System.arraycopy(element, index, element, index + 1, size - index);

50 Convert To A String public String toString() { StringBuffer s = new StringBuffer("["); // put elements into the buffer for (int i = 0; i < size; i++) if (element[i] == null) s.append("null, "); else s.append(element[i].toString() + ", "); if (size > 0) s.delete(s.length() - 2, s.length()); // remove last ", " s.append("]"); // create equivalent String return new String(s); }

51 Linear list Linked-Lists Representation

52 Definisi Linked list : linear list yang dibangun dari satu atau lebih node. Node terdiri dari dua bagian : data field dan pointer. Data field: bagian dari list node untuk menyimpan data. Pointer : bagian dari list node untuk menunjuk node berikutnya.

53 Node Link atau pointer data field

54 Single linked list Yaitu Linked list yang memiliki satu pointer. Pointer bantu : firstnode

55 Linked Representation pointer (or link) in e is null caedb use a variable firstNode to get to the first element a firstNode

56 Normal Way To Draw A Linked List link or pointer field of node data field of node abcde null firstNode

57 Linked Lists vs Array Menyimpan koleksi elemen secara non-contiguously. Elemen dapat terletak pada lokasi memory yang saling berjauhan. Bandingkan dengan array dimana tiap-tiap elemen akan terletak pada lokasi memory yang berurutan. Mengizinkan operasi penambahan atau penghapusan elemen ditengah-tengah koleksi dengan hanya membutuhkan jumlah perpindahan elemen yang konstan. Bandingkan dengan array. Berapa banyak elemen yang harus dipindahkan bila akan menyisipi elemen ditengah- tengah array? A0A1A2A3

58 Chain A chain is a linked list in which each node represents one element. There is a link or pointer from one element to the next. The last node has a null pointer. abcde null firstNode

59 Latihan Diketahui L=(a,b,c,d). L adalah sebuah linked lists.. Tentukan hasil yang didapatkan ketika dilakukan operasi berikut ini : a)isEmpty() b)size() c)get(0), get(2),get(6),get(-3) d)indexOf(a), indexOf(c), indexOf(q) e)remove(0), remove(2), remove(3) f)add(0,e), add(2,f), add(3,g), add(4,h), add(6,h), add(-3,h) (Gambarkan rangkaian node pembentuk linked list tersebut kondisi awal dan akhir tiap operasi)

60 Node Representation package dataStructures; class ChainNode { // package visible data members Object element; ChainNode next; // constructors come here } next element

61 Constructors Of ChainNode ChainNode() {} null element next element ChainNode(Object element) {this.element = element;} ChainNode(Object element, ChainNode next) {this.element = element; this.next = next;}

62 get(0) checkIndex(0); desiredNode = firstNode; // gets you to first node return desiredNode.element; abcde null firstNode

63 get(1) checkIndex(1); desiredNode = firstNode.next; // gets you to second node return desiredNode.element; abcde null firstNode

64 get(2) checkIndex(2); desiredNode = firstNode.next.next; // gets you to third node return desiredNode.element; abcde null firstNode

65 get(5) checkIndex(5); // throws exception desiredNode = firstNode.next.next.next.next.next; // desiredNode = null return desiredNode.element; // null.element abcde null firstNode

66 NullPointerException desiredNode = firstNode.next.next.next.next.next.next; // gets the computer mad // you get a NullPointerException abcde null firstNode

67 Remove An Element remove(0) abcde null firstNode firstNode = firstNode.next;

68 abde null firstNode c remove(2) first get to node just before node to be removed c c beforeNode = firstNode.next ; b beforeNode

69 remove(2) now change pointer in beforeNode beforeNode.next = beforeNode.next.next; beforeNode abcde null firstNode

70 add(0,’f’) abcde null firstNode f newNod e Step 1: get a node, set its data and link fields ChainNode newNode = new ChainNode(new Character(‘f’), firstNode);

71 add(0,’f’) abcde null firstNode f newNod e Step 2: update firstNode firstNode = newNode;

72 One-Step add(0,’f’) abcde null firstNode f newNod e firstNode = new ChainNode( new Character(‘f’), firstNode);

73 add(3,’f’) first find node whose index is 2 abcde null firstNode f newNode beforeNode c next create a node and set its data and link fields ChainNode newNode = new ChainNode(new Character(‘f’), beforeNode.next); finally link beforeNode to newNode beforeNode.next = newNode;

74 Two-Step add(3,’f’) beforeNode = firstNode.next.next; beforeNode.next = new ChainNode(new Character(‘f’), beforeNode.next); abcde null firstNode f newNode beforeNode c