Week 6a

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4122202 Data Sturcture Algorithms?????????????
???????????????

• Week 6a
• List Abstract Data Type
• ??????????????

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????? (Lists)

• Abstract Data Types (ADTs)
• ??????? set ??? objects ?????? set ???
  operations ???????????????? objects (???? lists,
  sets ??? graphs) ????????? operations ??????????
  objects ????????? ?????????? Abstract Data Type
  (ADT) ?????????
• Class ?? C ???????????????? ADT
  ??????????????????????? ??????????????????????????
  ??????????????????????????????? class
  ???????????? operation ?? ADT ????????????????????
  ??????????????????

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The List ADT

• List ?????????????????? A1, A2, A3,, AN ????
  List ???? N
• List ????? size 0 ??? Empty List
• Ai1 ??????? (Follows ???? succeeds) Ai (iltN)
• Ai-1 ?????? (Precedes) Ai (igt0)
• ?????? (Element) Ai ???????????????????? i ???
  List

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Set ??? operations ?????????? List

• PrintList() ??????????????? List ???????
• makeEmpty() ????????????? List ???????
• Find() ?????????????? List ?????????????????????
  ?
• ????????
• Insert() Insert ??????????????????????? List
• Delete() Delete ??????????????????????????????
  List

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Set ??? operations ?????????? List
??? List ?????????????? 34, 12, 52, 16, 12 ??????
Find(52) ?????? return ???? 3 Insert(X,3) ?????
List ???????? 34, 12, 52, X, 16,
12 Remove(3) ????? List ???????? 34, 12, X, 16, 12
????????????????? Operations ?????????????????
???? Next() ??? Previous() ?????????????????????
???????? (Argument) Next() return
??????????????????????????????? Previous() return
?????????????????????????????????????????
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???????? List ADT

• ?????????????? list ??? 2 ???? ??????
• ??????????????????? (Array Implementation of
  List)
• ????????????????????????? (Linked List
  Implementation of List)

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Simple Array Implementation of Lists

• ????????? list ??????????????????????????????????
  ???????? ?????????????????????????????????? array
  ???
• ?????? list ???? Size ??????????????? array ????
  gtSize

Array ???? N1 ???????????????????????? N1 ???
??????????????? 0 ??? N

• ?????????? C ????????????????? Array
  ?????????????????????
• ??????????????????????????????????????????????????
  ????
• ???????????????????????????

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Simple Array Implementation of List

• ????????
• ???????????? list ???????????????????????????
  (product) ????? 5 ???? ?????? computer, monitor,
  hub, router ??? ATM
• ??????????????? product ???? sizegt5 ??????

product 0
product 1
product 2
product 3
product 4
Computer
Monitor
Hub
Router
ATM
?????????????? list ??????????????????????????????
?
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Simple Array Implementation of Lists
Running Time ???????????????????????????????

• ??? Insert ?????????? list ?????????????

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Simple Array Implementation of Lists

• ??? Delete ?????? ? ???????????????? list

• ??? Insert ??? Delete ???????????????????????????
  ???????????????????????? ???? Linear Time, O(N)

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Simple Array Implementation of Lists

• ???????????????????? Insert ?????????????????????
  ????? N ????? ????????????????? O(N) ???????????
  O(N2)

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(No Transcript)
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??????????????????????????? (Linked List)

• ??????????????????????????? (series) ??? records
  ???? nodes ???????????????????????????????????????
  ???????????????????????? ???????? Record ????
  Node ?????????? 2 ???? ???
• Element ??? ????????????????? Record ???? Node
  ????????????Pointer ??? ??????????????? Record
  ???? Node ?????????????????????????? ????????
  Next Pointer
• ??? Pointer ?????????????????????????????????????
  nil ????????????? ????????? 0 ???????? nil

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??????????????? P ???? Pointer ????? Record
?????? ???????????????? P ???????????????????
main memory ??? Record ??? P ?????
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Operation ?? Linked List
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Insert() ??????????????????????????????????? Node
???????????????????? new ????????????????????
Next Pointer 2 ???????????
(3)
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Delete() ??????????????????????????????
????????????????Next Pointer 1 ???????????
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Header

• ????? Header ???? Dummy Node ???????? node ?????
  ?????????????????????????

Header ????????????????????? 0 ?????? ???? List
??????????? 4 ??? A1, A2, A3, A4 ????? Header
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Empty List

• Linked List ????????????????????? ????????????
  Empty List ??????????????? Dummy node ???? Header
  ???? ????? Linked List ?????????????????

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Type Declaration of Linked Lists
/Declare Function Prototype/ PointerToNode
makeEmpty(ptrToNode) Boolean isEmpty(ptrToNode)
Position find(TypeOfElement, ptrToNode) Position
findPrevious(TypeOfElement, ptrToNode) void
insert(TypeOfElement, ptrToNode, ptrToNode) void
delete(TypeOfElement, ptrToNode) void
deleteList(ptrToNode) Struct Node
TypeOfElement Element PointerToNode
Next
?????? Node ?????????????? Structure
????????????? 2 ????? ??? Element ?????????????
Next
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Programming Operations on Linked List

• ???????? List ??????????? Structure
  ????????????????????????

Struct Node ElementType element
Node next
List L ???? Pointer ????? List Position P ????
Pointer ????? Node Element X ?????????????????????
????? Node ?????
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Programming Operations on Linked List
???????????????????????????? Pointer
????????????????? -gt ????????????????????????????
? Pointer ?????
P
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???????????????????????????? Pointer
L
P
next
next
NULL
L-gtelement 25
L-gtnext P
30
P-gtelement
P-gtnext
NULL
30
L-gtnext -gtelement
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Test Empty List Test ??? Linked List ???? Empty
List ???????
Algorithm Boolean isEmpty(pointerToNode,
pointerToList) pointerToNode pointer to any
node pointerToList pointer to the list to be
tested Output True if the list is empty False
if the list is not empty Begin (return
PointerToList-gtnext equals NULL) End
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Programming Operations on Linked List
Test Empty List Test ??? Linked List ???? Empty
List ???????
Boolean isEmpty (node pointerToNode, node
pointerToList) return (pointerToList
NULL)
pointerToList-gtNext
NULL
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• Test Last Position ??????? Test ??? node ??
  Position P ???????????????????? List ???????

Algorithm Boolean isLast(pointerToNode,
pointerToList) pointerToNode pointer to any
node pointerToList pointer to the list to be
tested Output True if pointerToNode points to
last position in the list False if
pointerToNode not point to the last position in
the list Begin (return next of
pointerToNode equals NULL) End
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• Test Last Position ??????? Test ??? node ??
  Position P ???????????????????? List ???????

boolean IsLast(node P, node L) return
P-gtNext NULL
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• Find ??????????????????????? Element X ?????
  List

Algorithm pointerToNode find(target,
pointerToList) target value to
find pointerToList pointer to the
list Output pointerToNode pointer to the node
found Begin (set pointerToNode to start at
pointerToList) While(pointerToNode
is not NULL and element of pointerToNode is
not target) (Move pointerToNode to the
next node) (return
pointerToNode) End
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• Find Position ????????? (Position) ?????????
  Element X ????? List

Position Find( int X, node L ) node P
P L-gtNext while( P!NULL
P-gtElement ! X ) P P-gtNext return P
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• Find Previous Position ???????????? node
  ????????????????? Element X ?? List
  ??????????????????????? Null ????????????? Header

node findPrevious(int target, node
pointerToList) node pointerToNode pointerToN
ode pointerToList while((pointerToNode-gtnext
! NULL) (pointerToNode-gtnext-gtelement !
target)) pointerToNode
pointerToNode-gtnext return pointerToNode
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• Insertion Routine ???? node ?????? Element X
  ????????????????? P ????????????????? Header ????

void insert(int newElement, node pointerToList,
node pointerToNode) node tempCell tempCell
new node if(tempCell NULL) coutgtgtError
out of memory space!! else tempCell-gteleme
nt newElement tempCell-gtnext
pointerToNode-gtnext pointerToNode-gtnext
tempCell
X
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• Deletion ?? node ????? List ??????????????????
  Element X ??????????????????? Header ????

void delete(int target, node pointerToList) no
de pointerToNode pointerToNode
findPrevious(target, pointerToList) tempCell
pointerToNode-gtnext pointerToNode-gtnext
tempCell-gtnext delete(tempCell)
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Deletion of the List ????? List ???????

• ????????? Delete ??????

void deleteList( pointerToList) node p p
pointerToList-gtnext pointerToList-gtnext
NULL while(p!NULL) delete(p) pp-gtnext

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Deletion of the List
void DeleteList( List L ) Position P,
Tmp P L-gtNext L-gtNext
NULL while( P ! NULL ) Tmp
P-gtNext free(P) P Tmp

• ????????? Delete ??????????

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???????????????? (Doubly Linked List)

• Linked list ??????????????????????????????????????
  ?????? (Traverse) ???? Linked list ?????????????
• ??????????????????? (data member)
  ???????????????????? Node ????????? pointer
  ??????????? Node ????????

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?????????????????? (Circular Linked List)

• ????? Application ?????????? Link ??? node
  ??????????????????? node ?????? list
• ?????????????????????????? Header ???????? Header