White Spaces

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CS 1430: Programming in C++

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Find Max, Min, Average of m Sections

Max, Min and Average of each section

Max, Min and Average of all sections together

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Pseudo Code

While not end of class

Process one section

While not end of class

While not end of section

Process one score

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Pseudo CodeInitialize class variables (LCV)

While not end of class

Initialize section variables (LCV)

While not end of section

Process one score

Update section LCV

Process and display section result

Process class variables

Update class LCV

Process and display class result

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Input

50.5 54 39 47.5 -1 50 49.5 52 -1 38 49 -1 50 59.5 53 60 -1 -2

Sentinel-Controlled Loop -1: end of section -2: end of class Range is not known All scores are valid

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Pseudo Code

classTotal = 0, classCount = 0Input a score (Prime Read)While score not -2 secTotal = 0 secCoumt = 0 While score not -1 Update secCoumt, secTotal, secMax, secMin Input next score Process and display section result Update classMax, classMin, classCount, classTotal Input next scoreProcess and display class result

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// Constants // Before main()const int END_CLASS = -2;const int END_SECTION = -1; int main(){ // Declare variables // Inside main() float score; float classMax, classMin, classTotal; float secMax, secMin, secTotal; int classScoreCount, secScoreCount;

… return 0;}

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classTotal = 0.0;classScoreCount = 0;cin >> score; // Prime Read

while (score != END_CLASS){ secTotal = 0; secScoreCount = 0; while (score != END_SECTION) { if (secScoreCount == 0) { secMax = score; secMin = score; } else { if (score > secMax) secMax = score; if (score < secMin) secMin = score; } secScoreCount ++; secTotal += score;

cin >> score; }

// Display section result

if (classScoreCount == 0)

{

classMax = secMax;

classMin = secMin;

}

else

{

if (secMax > classMax)

classMax = secMax;

if (secMin < classMin)

classMin = secMin;

}

classTotal += secTotal;

classScoreCount += secScoreCount;

cin >> score;

}

// Process and display class result

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Different Input

4 4 50.5 54 39 47.5 3 50 49.5 52 2 38 49 4 50 59.5 53 60

Count-Controlled Loop Range is known Checking range Ignore invalid scores Can you do it?

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White Spaces

SpaceTab

Next line…

(Replace Tab with 3 spaces in VS)

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Input Operator >>

cout << "What is your input: ";

cin >> theInput;

// Operator >> will ignore white spaces // before reading// Operator >> will stop at white spaces// after have read any value

// Input: -50.5 50

// What is the value of theInput?

// Depending on the type of theInput

// But the spaces before “-50.0” will be ignored.

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Type char

char theInput;

cout << "What is your input: ";

cin >> theInput;

// Input: -50.5 50

// Q: What is the value of theInput?

// A: _____

// ‘-’

// Not space before ‘-’

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Type integer

int theInput;

cout << "What is your input: ";

cin >> theInput;

// Input: -50.5 50

// Q: What is the value of theInput?

// A: _____

// -50

// stop at ‘.’, which cannot be part of int

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Type float

float theInput;

cout << "What is your input: ";

cin >> theInput;

// Input: -50.5 50

// Q: What is the value of theInput?

// A: _____

// -50.5

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Type string

string theInput;

cout << "What is your input: ";

cin >> theInput;

// Input: -50.5 50

// Q: What is the value of theInput?

// A: _____

// -50.5

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// Input// CS 143// X

char aChar;int count = 0;

cin >> aChar; // Prime read before loopwhile (aChar != ‘X’){ count ++; cout << aChar;

cin >> aChar;}cout << aChar;cout << “Count: “ << count;

Tracing

aChar

C

S

1

4

3

X

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Function cin.get()

The function will read one char at a time

Including white spaces!

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// Input// CS 143// X

char aChar;int count = 0;

cin.get(aChar);// Prime read before loopwhile (aChar != ‘X’){ count ++; cout << aChar; cin.get(aChar);}cout << aChar;cout << “Count: “ << count;

Tracing

aChar

C

S

-

1

4

3

\n

X

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Function cin.eof()

The function returns true or falseeof(): end of file

end of input

From keyboard[CTRL-D]

From FileNot True after reading the last item in the file

True when trying to read after reading the last item in the file

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// Input// CS 143// X

char aChar;int count = 0;

cin.get(aChar);// Prime read before loopwhile (!cin.eof()){ count ++; cout << aChar; cin.get(aChar);}cout << aChar;cout << “Count: “ << count;

Tracing

aChar cin.eof()

C False

S False

- False

1 False

4 False

3 False

\n False

X False

? True

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int theInput; int count = 0;

cout << "What is your input: "; cin >> theInput;

while (!cin.eof()) { count ++; cout << "What is your input: "; cin >> theInput; }

cout << theInput;cout << “Count: “ << count;

// Input: 55 50.5 60// What is the value of theInput?// Trouble when reading ‘.’!

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Formatting Output

cout << endl << "My output.";

cout << "\nMy output.";

float average;

int count;

// Compute count and average

cout << endl << count;

cout << endl << average; // How many digits displayed for average?

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#include <iomanip>

cout << fixed << showpoint << setprecision(2);

// Always display two decimal digits.

// No need to remember for quiz/test

float value;

value = 1 / 3.0;

cout << "\nFloat value 1/3.0: " << value;

// 0.33

value = 36 / 3.0;

cout << "\nFloat value 36/3.0: " << value;

// 12.00

value = 1 / 5.0;

cout << "\nFloat value 1/5.0: " << value;

// 0.20

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#include <iomanip> cout << fixed << showpoint << setprecision(2); // The setting is applied to all values displayed// until the setting changes.

float value;

value = 1 / 3.0;cout << "\nFloat value 1/3.0: " << setw(8) << value;// □ □ □ □ 0.33

value = 36 / 3.0;cout << "\nFloat value 36/3.0: " << setw(8) << value;// □ □ □ 12.00

value = 1 / 5.0;cout << "\nFloat value 1/5.0: " << value;// 0.20 (no extra spaces)

// setw() is only applied to the next value// It has to be used for every value need the format.

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Schedule• Prog1

Can still fix style

• Prog2: Loops

Start Early! Two points Quiz Monday!

• Lab 2

Demo by 4pm

• Quiz3-4

Due 5 pm Monday

• Test 1: Next Friday

Note01 – Note10

Prog2: Loops!

• Quiz3-5

Now!