?????????????????? Queue

1
?????????????????? Queue
Data Structure
Department of Computer Science
2
??????????????????????????? Queue

• ??????????????? Queue ????????????????????????????
  ?????????????????????????? ?? ?????????????????
  Queue ???????????????????????????? queue
  ?????????????????? ???????? ??????????????????????
  ??? FIFO (first-in-first-out)

Data Structure
Department of Computer Science
3
Operation ??? Queue

• 1. Insert ???? operation ???????????????????????
  Queue
• 2. Delete ???? operation ????????????????????
  Queue
• ????? Insert ??? Delete ?????????? 2 ?????? ???
• 1. ??????????????????????????????????????????
  Queue (Front)
• 2. ????????????????????????????????????????
  Queue (Rear)

Data Structure
Department of Computer Science
4
??????????????????? Operation Insert ??? Delete
(???????????????? Queue ?? 5 ?????)
5
Implementation Queue

• ??? Implement Queue ????? 2???????1. Array
  Implementation2. Linked List Implementation

Data Structure
Department of Computer Science
6
Insert Algorithm

• Array Implementation Insert Algorithm
• 1. ?????????? Queue ???? ? ( Rear N)
• - ??? Queue ???? ????????????????? "Queue
  Overflow" ???????????
• - ??? Queue ??????? ?????????????? 2 ??? 3
• 2. ?????????????? Rear ??? 1
• 3. ????????????? Queue ?????????????????? Rear

Data Structure
Department of Computer Science
7
Flowchat
Data Structure
Department of Computer Science
8
?????????????????????? Queue ??? Integer

• Program Pascal
• Procedure Insert ( X ) BeginIf RearN Then
  Writeln ( " Queue Overflow " ) ElseBeginRear
  Rear 1 Queue Rear X EndEnd

Data Structure
Department of Computer Science
9
?????????????????????? Queue ??? Integer

• Program C,C
• Insert ( int X )if (Rear N) printf ( "
  Queue Overflow " )elseRear Rear 1
  Queue Rear X

Data Structure
Department of Computer Science
10
Delete Algorithm

• Array Implementation Delete Algorithm
• 1. ?????????? Queue ???? ? (????????????????
  Front Rear)
• - ??? Queue ???? ????????????????? "Queue
  Empty" ???????????
• - ??? Queue ??????????? ?????????????? 2 ??? 3
• 2. ????????????????? Front
• 3. ??????????????????????? Front ?????? Queue

Data Structure
Department of Computer Science
11
Flowchat
Data Structure
Department of Computer Science
12
?????????????????????? Queue ??? Integer

• Program Pascal
• Procedure Delete(var X inteer ) BeginIf
  Front Rear Then Writeln ( " Queue Empty " )
  ElseBeginFront Front 1 X QueueFront
  EndEnd

Data Structure
Department of Computer Science
13
?????????????????????? Queue ??? Integer

• Program C,C
• Delete ( )if (Front Rear) printf ( "
  Queue Empty " )elseFront Front 1 X
  Queue Front

Data Structure
Department of Computer Science
14
Circular Queue (????????)
15
Circular Queue (????????)

• ???????????????????????????????
• ??????????????????????????????????????????
  ????????????????????
• ????????????????????? ?????????????????????
• ??????????????????????????? (Full Queue)
  ??????????????????????
• ???????????????? ?????????? F ???????????????????
  ?????? ????????????????
• ??????????????????????????????????????????????????
  ??????????????
• (Empty Queue) ???????????????????????????????? F
  ??? R ????????????
• ?????????????????????? ???????????????????????????
  ?????????????????????
• ????? F ?????? ???????????????????????????????????
  ????? F ????????????
• ??????????? (????????????) ???????????????????????
  ?????????

16
Circular Queue (????????)

• ??????????????????????? ?????????????????????????
  ???????????????
• ???????????? ?????????????????????????????????????
  ?????????????????
• ??????????????????????????? ???
  ???????????????????? (Front)
• ??????????????????????? (Rear)
  ???????????????????????????
• ???????? ???????? (Circular Queue)

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Circular Queue (????????)

• ??????????
• ??????????????????????????????????????????????????
  ?????????????????? 6 ?????????????
  ??????????????? 0-4 ?????? ??????????????????
  ??????????????????????????????????????????? ????
  ???????????????????????????????? 100 ????
  ??????????????????????????????????????? 100
  ?????????? ??????????????????????? ???????????
  ?????? (Delete) ?????????????????????????????????
  90 ???? ????????????????????? 7 ??
  ???????????????? ???????? ??????????????????? 3
  ?? ????????? 100 ?? ??????????????????????????????
  ????? 90 ???? ?????? ?????????????????????? 90 ??
  ????????????????????????????????? ?????
  ?????????????? 100 ???? ???????????????????
  ?????????? 100 ??????????

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Circular Queue (????????)

• ?????????????????????? ???????????????????????????
  ??????????????????????????????????????
  ????????????????????????? ???? ????????????????/??
  ?????????????? ???????????????????????????????????
  ?? 6 ??? (6 ??) ????????????????????
  ????????????????????????????????????????????? ?
  ??????????????

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Circular Queue (????????)

• ???????????? A-F ???????? 1 - 6 ?????????? 1 ???
  A ????????????????(?????????) ?????????? A
  ???????????? ?????????????????????????????????????
  ????????? A ??????? ????????????? ????? B
  ???????????????? ??????????????????
  ?????????????? B ??????? ???????????????? ?
  ??????????????? ?????????????? ???????????????????
  ????? ???????? (Circular Queue)

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???????????Operation??? Circular Queue

• ???????????????????????????????1. FIFO (First In
  First Out) ???????????????2.
  ????????????????????????? insert ???????? Queue
  ??? 3. ????????????????? queue ?????????????????
  1 ?????? ? ?????? ??????????? queue
  ??????????????????????????????????? queue
• Operation ??? circular queue1. Insert
  ???????????????????? (?????)2. Delete
  ??????????????????????? (??)

21
?????????????????????????? Circular Queue

• ???????????????? Queue ????????????? 6 ???
  ???????????????????? 0 ????????? 5

22
?????????????????????????? Circular Queue
23
?????????????????????????? Circular Queue
24
?????????????????????????? Circular Queue

• ?????????????????????????? ???????????????? Front
  ??? Rear ???????????????????

???????? Error E ??????? Queue Empty Error O
??????? Queue Overflow
25
Algorithm Insert

• Algorithm Insert1. ????????????????? ? (
  ??????????????? Rear Front ? )-
  ??????????????????????????? "Queue Overflow"
  ????????????????2. ?????? Rear ??????????3.
  ??????????????????4. ?????????? Front ???? -1
  ??????? (???????????????????????????????????????)
  - ?????? ??? Front 0 ( Front ???????????????????
  ??????????)

26
Flowchart Insert
27
Program

• ???? Pascal
• Procedure insert ( x integer) var next
  integerBeginnext (rear1) mod 5 if
  nextfront then write ( ' Queue Overflow ' )else
  beginrear next queuerear x if front
  -1 then front0endEnd

28
Program

• ???? C
• Insert(int x) int nextnext (Rear1) n
  if (next Front) printf(" Queue Overflow
  ")return 0Rear next QueueRear x
  if (Front -1) Front 0

29
Algorithm Delete

• Algorithm Delete1. ???????????????????????? ?
  (Front -1 ? )2. ?????????????????3.
  ???????????????????????????????????????????
  (Front Rear ? )- ?????? ??? Front ??? Rear
  ???? -1 (???????????????????????????)- ?????????
  ????????? Front ??????????????

30
Flowchart Delete
31
Program

• ???? Pascal
• Procedure delete (Var x integer) Beginif
  front -1 then write ( ' Queue Empty ' ) else
  beginx QueueFront if frontrear
  thenbegin front -1 rear -1 end else
  front (front1) mod 5end End

32
Program

• ???? C
• Delete()if (Front-1) printf(" Queue Empty
  " )return 0x QueueFrontif
  (FrontRear) FrontRear-1else Front
  (Front1) n return x