05-530-111 Computer Programming 1

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05-530-111 Computer Programming 1
????? 3???????????????(Control Structures)
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???????????

• 3.1 ?????????? (Algorithm)
• 3.2 ????????? (Pseudocode)
• 3.3 ??????????????? (Control structure)
• 3.4 ????????????????? (Sequence structure)
• 3.5 ???????????????????? if
• 3.6 ???????????????????????? switch
  

3
???????????

• 3.8 ???????????????????? while
• 3.7 ???????????????????? for
• 3.9 ???????????????????? do/while
• 3.10 ?????? break ??? continue

4
???????????

• 3.11 ?????????????????? (Formulating Algorithm)
• ????????? 1, ???????????????????????
  (Case Study 1,
  Counter-Controlled Repetition)
• 3.12 ????????????????????????????????????????????
  ?? (Formulating Algorithm with Top-Down, Stepwise
  Refinement)
• ????????? 2, ???????????????????????????
  (Case Study 2, Sentinel-Controlled
  Repetition)
• ????????? 3, ??????????????????????
  (Case Study 3, Nested
  Control Structure)

5
3.1 ?????????? (Algorithm)

• ?????????????????? ??? ???????????????????????????
  ????????????????????
• ????????
• ????????????????

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3.2 ????????? (Pseudocode)

• ????????? ??? ??????????????????????
  ?????????????????????????????????????????
• ??????????????????????????????????????
  ?????????????????????????????? ???????????????????
  ?????????????????????? ?
• ????????????????????? ???????????????????????????
  ??? ??????????????????????????
  ??????????????????????????????????????????????????
  ???????????????????????????????? (???? C ????
  Java) ???????????? ???????????????????????????????
  ?????????????????? ?

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3.3 ??????????????? (Control structure)

• ??????????????????????????????????????????????????
  ?????????????????? 3 ???????????? ???
• ????????????????? (Sequence structure)
• ????????????????? (Selection structure)
• ????????????????? (Repetition structure)

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3.4 ????????????????? (Sequence structure)

• ??????????????????????????????????????????????????
  ?????????????? ???????????????????????????????????
  ???????????????????

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???????? Flowchart ?????????????????????????????
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3.5 ???????????????????? if

• ???????????????????? if ??? ??????????????????????
  ????????? (???????????????) ??????????????????????
  ???? ?????? 3 ?????????
• 1. ????????????? (One Alternative)
• 2. ??????????? (Two Alternative)
• 3. ???????????? (Multiple-Alternative)

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3.5.1 ???????????????????? if ?????????????

• ??????????????? ??????????????? (???????????????)
  ?????????? ???????????????????????????
• ???????? Flowchart ??????????????????????? if
  ?????????????

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????????????????????????????? if ?????????????

• ??????????? 1 ??????
• if (condition)
  Statement T

??????????????????????
if (condition)
True task
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??????????????????????????????? if ?????????????

• ????????1
• if (x gt 0)
• total total x

????????2 if (xgty)
tempx xy ytemp
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3.5.2 ???????????????????? if ???????????

• ???????????????????????????? ????????
  ????????????? (???????????????)
  ???????????????????????????????? ???? ????????
  (???????????????) ????????????????????????????????
  
• ???????? Flowchart ??????????????????????? if
  ???????????

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????????????????????????????? if ???????????

• ??????????? 1 ??????
• if (condition)
• statement T
• else
• statement F

??????????????????????
if (condition) true
task else
false task
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??????????????????????????????? if ???????????

• ????????1 if (x gt 0)
• cout ltlt "positive\n
• else
• cout ltlt negative\n

????????2 if (xgty) temp x xy
ytemp else countcount 1
cout ltlt "smaller\n
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3.5.3 ???????????????????? if ????????????

• ????????????????????????????? ????????
  ???????????????????????????? ?????????????????????
  ????????????????? 2 ???????? ?????????????????????
  ???????? if ??????????????????????????????????????
  ? MultipleAlternative

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????????????????????????????? if ????????????

• ??????
• if (condition 1)
• statement 1
• else if (condition 2)
• statement 2
• else if (condition n)
• statement n
• else
• statement

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??????????????????????????????? if ????????????

• /increment mum-pos, num_neg, or num_zero
  depending on x/
• if (x gt 0)
• num_pos num_pos 1
• else if (x lt 0)
• num_neg num_neg 1
• else
• num_zero num_zero 1

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3.6 ???????????????????????? switch

• ???????????????????????? switch
  ????????????????????? ????????????????????????????
  ???????? ??????????????????? ???????????????????
  (int) ???? ??????????????????(char)
  ???????????????????????????????(double)
  ??????????????????????????, ??????
  ?????????????????

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????????????????????????????????? switch

• ?????? switch (controlling expression)
• case lable_set1
• statements1
• break
• case label_set2
• statements2
• break
• case lable_setn
• statementsn
• break
• default

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??????????????????????????????????? switch

• ???????? switch (class)
• case B
• case b
• cout ltlt "Bat\n
• break
• case C
• case c
• cout ltlt "Cat\n
• break
• default
• cout ltlt "Unknown class \n ltlt class

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3.7 ???????????????????? for

• ????????????????????????????????????
  ?????????????????????? ???????????????????????????
  ???? 3 ???????
• 1. ??????????????????????????????????
• 2. ???????????????????
• 3. ?????????????????????????????????????????

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?????????????????????????? for

• ?????? for (initialization expression
  loop repetition condition
  update expression)

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???????????????????????????? for

• ???????? /Display N asterisks/
• for (count 0
• count lt 10
• count 1)
• cout ltlt ""
• ???? for (count 0 count lt10 count
  1)
• cout ltlt ""
• ???????

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???????????????????????????? for

• ???????? /Display Round No./
• for (i 1 i lt5 i 1)
• cout ltlt Round ltlt i ltlt endl
• ???????
• Round 1
• Round 2
• Round 3
• Round 4

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3.8 ???????????????????? while

• ??????????????????????????????????????? ?
  ????????????????????????? ????
• ???????????????????????????????????????? (????)
  ???????????????????????????????????
• ????????????????????????????????????????? (????)
  ??????????????????????????????????
  ???????????????????????????????????????? while ???

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?????????????????????????? while

• ?????? while (loop repetition condition)
• statement

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???????????????????????????? while

• ???????? /Display N asterisks./
• count 0
• while (count lt 10)
• cout ltlt "
• count count 1
  
• ???????

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???????????????????????????? while

• ???????? /Display Round No./
• i 1
• while (i lt 5)
• cout ltlt Round ltlt i ltlt endl
• i i 1
• ???????
• Round 1
• Round 2
• Round 3
• Round 4

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3.9 ???????????????????? do/while

• ???????????????????? while ??? for
  ??????????????????????????????????????????????????
  ????? ????????????????? (???????????) ????????
  ??????????????????????????????????????????????????
  ????? 1 ????? ???????????????????????????????????
  ??????????? do-while ???

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?????????????????????????? do/while

• ?????? do statement
• while (loop repetition condition)

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???????????????????????????? do/while

• ???????? / Display Round No./
• i1
• do
• cout ltlt Round ltlt i ltlt endl
• i i 1
• while ( i lt 5)
• ???????
• Round 1
• Round 2
• Round 3
• Round 4

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3.10 ?????? break ??? continue

• ?????? break ?????????????????????????????????????
  ?????????????????????????????? ??????????????
  
• break
• ?????? continue ??????????????????????????????????
  ?????????????????????? ???????????????????????????
  ???? ??????????????
• continue

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3.11 Formulating Algorithm

• ????????? 1, ???????????????????????
• ????????????????????????????????? while ????
  do/while ????????????????????????????????? ??????
  (Counter) ????????????????????????????????????????
  ? ???????????????????????????????????
  ??????????????????????????????????????????????????
  ??

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????????????????? 1, ???????????????????????

• ?????
• ??????????????????????????????? 10
  ??????????????????????????????????????????????????
  ????????????????? 0 ??? 100
• ????????????????????????
• ????????????????????, ????????????????
  ???????????????????? ????????????????????????????
  ????????????????? ????????????????????????????

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????????????????? 1, ???????????????????????

• / Class average program with counter-controlled
  repetition /
• include ltiostream.hgt
• int main()
• int counter, grade, total, average
• / initialization phase /
• total 0
• counter 1
• / processing phase /
• while (counter lt 10)
• cout ltlt "Enter grade "
• cin gtgt grade
• total total grade
• counter counter 1

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????????????????? 1, ???????????????????????(???)

• / termination phase /
• average total / 10
• cout "Class average is " ltlt average ltlt endl)
• return 0 / indicate program ended
  successfully /

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???????????????? 1, ???????????????????????

• Enter grade 98
• Enter grade 76
• Enter grade 71
• Enter grade 87
• Enter grade 83
• Enter grade 90
• Enter grade 57
• Enter grade 79
• Enter grade 82
• Enter grade 94
• Class average is 81

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3.12 Formulating Algorithm with Top-Down Stepwise
Refinement

• Top-Down Stepwise Refinement ?????????????????????
  ???????????????????????????????????????
• ???????? pseudocode ??????????????????????
  ?????????????????????????
• ??????????????? ??????? pseudocode
  ??????????????????????????????????????????????????
  ???????????????????????????????????

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????????? 2 ???????????????????????????

• ????????????????????????????????? while
  ???? do/while ?????????????????????????????????
  ?????????? (sentinel value) ??????????????????????
  ????????????????????

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????????????????? 2, ???????????????????????????

• ?????
• ?????????????????????????????????????????????????
  ?????????????? 1 ?????????????????????????????????
  ???????
• ????????????????????????
• ????????????? ???????????????????????????????????
  ??????? ????????????????????????????????
  ?????????????????????????? ???????????????????????
  ????????????????????????

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?????????????????????????? 2
?????????????????? total ???????
0 ?????????????????? counter ???????
0 ???????????????????? While ?????????????????????
?????????????? ???????????????
total ??????????? counter ????????? ????????????
???? (????????????????????????????) If counter
?????????? 0 ???????? average ??????? total
??????? counter ????? average Else ????? No
grades were entered (??????????????????????????)
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????????????????? 2, ???????????????????????????

• / Class average program with sentinel-controlled
  repetition /
• include ltiostream.hgt
• int main()
• float average / new data type /
• int counter, grade, total
• / initialization phase /
• total 0
• counter 0
• / processing phase /
• cout ltlt "Enter grade, -1 to end "
• cin gtgt grade
• while (grade ! -1)
• total total grade
• counter counter 1
• cout ltlt "Enter grade, -1 to end "
• cin gtgt grade

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????????????????? 2, ???????????????????????????(?
??)

• / termination phase /
• if (counter ! 0)
• average (float) total / counter
• cout ltlt Class average is ltlt average
• else
• cout ltlt "No grades were entered\n"
• return 0 / indicate program ended successfully
  /

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???????????????? 2, ???????????????????????????

• Enter grade 75
• Enter grade 94
• Enter grade 97
• Enter grade 88
• Enter grade 70
• Enter grade 64
• Enter grade 83
• Enter grade 89
• Enter grade -1
• Class average is 8250

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????????? 3 ??????????????????????

• ????????????????????????????????????????????
  ?????????????????????????? ? ???
  ??????????????????????????????????????????????????
  ?????????????????????????????????????

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????????????????? 3, ??????????????????????

• ?????
• ????????????????????????????????????????????????
  ???????????????????????????????
  ??????????????????????????? 10 ??
• ???????????????????????? ???????????????????????
  1 ?????????
• ?????????????????????? ???????????????????????
  2 ?????????
• ?????????????????????????? 8 ?????????
  ??????????????? Raise tuition
• ????????????????????????
• ??????????? (??????? ??? 1 ???? 2) ??????
  ??????????? Enter result (???????????)
  ??????????????????????????????????????????????????
  ??
• ????????????????????????? (?????????)
• ???????????????? ????????????????????????????????
  ?????????????????????
• ?????????????????? 8 ????????? ???????????????
  Raise tuition (????????????????)

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?????????????????????????? 3
?????????????????? passes (???????????????)
??????? 0 ?????????????????? failures
(?????????????) ??????? 0 ??????????????????
student counter ??????? 1 While student counter
??????????????????? 10 ?????????????????????? I
f ??????????????? ????????????????
passes Else ????????????????
failures ???????????????? student
counter ????????????? passes ?????????????
failures If ??????????????? 8 ????????? ?????
Raise tuition
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????????????????? 3, ??????????????????????

• / Analysis of examination results /
• include ltiostream.hgt
• int main()
• / initializing variables in declarations /
• int passes 0, failures 0, student 1,
  result
• / process 10 students counter-controlled loop
  /
• while (student lt 10)
• cout ltlt "Enter result (1pass, 2fail) "
• cin gtgt result
• if (result 1) / if/else nested in while
  /
• passes passes 1
• else
• failures failures 1
• student student 1

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????????????????? 3, ??????????????????????

• cout ltlt Passed ltlt passes
• cout ltlt "Failed " ltlt failures)
• if (passes gt 8)
• cout ltlt "Raise tuition\n"
• return 0 / successfully termination /

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???????????????? 3, ??????????????????????

• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 2
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Enter Result (1pass, 2fail) 1
• Passed 9
• Failed 1
• Raise tuition