Examples Rules More examples

• Examples

• Rules

• More examples

Program structureProgram structure

Program structureProgram structureTransfering the problem into code

• Split the problem into smaller problems

• Make a structure of the problems (indata/outdata)

• Write down an operationlist and the conditions

?

Program structureProgram structureTransfering the problem into code

• Split the problem into smaller problems

• Make a structure of the problems (indata/outdata)

• Write an operationslist and the conditions

• Pseudocode can be used

?

What is pseudocode? What is pseudocode?

• Pseudocode is a combination between ordinary language and real programcode

• The pseudocode includes the sequences,selections, iterations, conditions and operationsplaced in the structurediagram

• Pseudocode can be used to simplify thestructured problem before it becomes real programcode

Milk the cow - Milk the cow - PseudocodePseudocodePeasant needs

money


money

Milk thecow

Operationlist

Conditionlist

1. Input peasant_tired value2. Read selection (hand/machine)3. Input milk value4. Squeeze5. Read milk value6. Squeeze7. Read milk value

1. If peasant_tired = yes (sel bm)2. While milk = exist3. While milk = exist

1

By machine By hand

IF peasant_tired= yes

ELSE

Squeeze Squeeze* *WHILE milk = exist

WHILE milk = exist

4 5 6 7

2 3


money

Milk thecow

By hand

ELSE

Squeeze*WHILE milk = exist

6 7

IFneighbour_home = yes

Operationlist

Conditionlist

8. Input neighbour_home value9. Read selection (neighbour/village)10. Sell to neighbours11. Sell to village 12. Input money value

4. If neighbour_home = yes

Sell milk

To neighbours To village

ELSE

10 12 11 12

2 3 98


Operationlist

Conditionlist

13. Buy clothes14. Read money value

5. While money = exist

Spend money

Buy clothesfor wife

* WHILE money = existTo neighbours To village

ELSE

money

If neighbour _home

Sell milk

10 12 1211 1413

98


money

Milk thecow

Sell milk

By machine By hand

IF peasant_tired = yes

ELSE

Squeeze Squeeze* *WHILE milk = exist

WHILE milk = exist

IF neighbour_home = yes

To neighbours To village

ELSE

Spend money

Buy clothesfor wife

*WHILE money = exist

PseudocodePseudocode

1. If peasant_tired = yes (sel bm)2. While milk = exist3. If neighbour_home = yes4. While money = exist

Conditionlist


8. Input neighbour_home value9. Read selection(neighbour/village)10. Sell to neighbours11. Sell to village 12. Input money value

1. Input peasant value2. Read selection (hand/machine)3. Input milk value4. Squeeze5. Read milk value6. Squeeze7. Read milk value

Operationlist

PEASANT NEEDS MONEY

Input peasant value IF peasant_tired = yes milk with machine ELSE milk by hand ENDIFInput milk value WHILE milk = exist Squeeze Read milk value ENDWHILE Input neighbour_home IF neighbour_home = yes sell milk to neighbours ELSE sell milk in village ENDIFInput money value WHILE money = exist Buy clothes for wife

Read money value ENDWHILE



Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY





Conditionlist




Operationlist

PEASANT NEEDS MONEY



PEASANT NEEDS MONEY





Conditionlist




Operationlist

OK!How about some real programcoding?

The endpart 2

• Structure diagram

• Structure diagram to pseudocode

• Pseudocode to C programming

Solving 2nd degree equationsSolving 2nd degree equations

C

Solving 2nd degree equationsSolving 2nd degree equationsProgram structure

y = ax +bx +c2

2nd degree equation

0

04 4

02 4

2 4

2 4

2 4

2

2

2

2

2

22

2

22

2

2

2

2

2

a xb

ax

c

a

xb

ax

b

a

b

a

c

a

xb

a

b

a

c

a

xb

a

b

a

c

a

xb

a

b

a

c

a

xb

a

b

a

c

a

( )

( )

( )

( )

0 = ax +bx +c2

D


0 = ax +bx +c2

Information

2nd degree equation


0 = ax +bx +c2

Solve equation?

One equation*While answer n or N

Information

2nd degree equation


0 = ax +bx +c2

Possible solution

Solve equation?


Information

Constant a Constant cConstant b

2nd degree equation


0= ax +bx +c2

Possible solution

Solve equation?


Information


If D 0

Solution No real solution

D = b²/(4a²)-c/a

2nd degree equation


0 = ax +bx +c2

Possible solution

Solve equation?


Information


If D 0


One solution

If D 0

Two solutions

D = b²/(4a²)-c/a

2nd degree equation


0 = ax +bx +c2

Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions

D = b²/(4a²)-c/a

Solving equationsSolving equations

Pseudo coding

Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions

Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a If D 0 If D = 0 calculate x = -b/(2a) display x else calculate x1= -b/(2a)+D calculate x2= -b/(2a)-D display x1, x2

end if else display No solution end if Ask if user would like to solve an equation (y/n) end while

Rotate and Flip


Pseudo coding

Pos

sib

le s

olu

tion

2n

d d

eg

ree

eq

uatio

n

Sol

ve e

qua

tion

?

One

eq

uatio

n*

Whi

le a

nsw

er

n o

r N

Info

rma

tion

1

Con

sta

nt a

3

Con

sta

nt c

5

Con

sta

nt b

4If

D

0

Sol

utio

nN

o re

al s

olu

tion

11

2

2

One

so

lutio

n

If D

0 7

86

910T

wo

so

lutio

ns



Rotate and Flip

DivisionDivision

TimeTime


Pseudo coding

Solving 2nd degree equationDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a If D 0 If D = 0 calculate x = -b/(2a) display x else calculate x1= -b/(2a)+D calculate x2= -b/(2a)-D display x1, x2


Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding


end if else display No solution end if Ask if user would like to solve an equation (y/n)end while

Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions


Pseudo coding



Possible solution

2nd degree equation

Solve equation?


Information

1

Constant a

3

Constant c

5

Constant b

4If D 0


11

2

2

One solution

If D 0

7 8

6

9 10

Two solutions

Lego MindstormsLego Mindstorms

Lego MindstormsLego Mindstorms

Here’s an example of translating the pseudocode to C code


C

c:\windows\system\cool.dllProgram

Solving equationsSolving equations C coding

Solving 2nd degree equations

int main(){ char answer;

I’m lost in cyberspace













Solving 2nd degree equationsDisplay program information

int main(){ char answer; info();

Don’t worry!You’ll C!!

void info(void){ printf(”\nThis program will solve equations of the 2nd degree”); printf(”\n in the form of ax^2+bx+c=0.”); printf(”\nReturns only real values.”); printf(”\n”);}


Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)

int main(){ char answer; info(); answer=ask_again();

Aha, this doesn´t seemto be that difficult!

char ask_again(void){ char c; printf(”\n Do you want to solve an equation? (y/n)”); while((c=getchar())==’\n’); return c;}




Make room! I’ve got more to say!








Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N

int main(){ char answer; info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) {











Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c


info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, a, b, c);


Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a


info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, &a, &b, &c); D = pow(b, 2)/(4*pow(a,2))-c/a;


Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a If D 0 If D = 0

else

end if else

end if


info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, &a, &b, &c); D = pow(b, 2)/(4*pow(a,2))-c/a; if (D >= 0) { if (D == 0) {

} else {

} } else { }

If and else?I don’t get it!



else

end if else

end if



} else {

} } else { }

If and else?I don’t get it!

Wait, check this out!



else

end if else

end if



} else {

} } else { }

Voila!

calculate x = -b/(2a)display x

x = -b/(2*a);printf(”One solution X:%.2lf \n”, x);


Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a If D 0 If D = 0 calculate x = -b/(2a) display x else

end if else

end if


info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, &a, &b, &c); D = pow(b, 2)/(4*pow(a,2))-c/a; if (D >= 0) { if (D == 0) { x = -b/(2*a); printf(”One solution X:%.2lf\n”, x); } else {

} } else { }

calculate x1= -b/(2a)+Dcalculate x2= -b/(2a)-Ddisplay x1, x2

x1 = -b/(2*a)+ sqrt(D);x2 = -b/(2*a)- sqrt(D);printf(”Two solutions X1:%.2lf X2:%.2lf\n”, x1, x2);


Solving 2nd degree equationsDisplay program informationAsk if user would like to solve an equation (y/n)While answer is not n or N Input constant a Input constant b Input constant c calculate D = b²/(4a²)-c/a If D 0 If D = 0 calculate x = -b/(2a) display x else calculate x1= -b/(2a)+D calculate x2= -b/(2a)-D display x1, x2 end if else

end if


info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, &a, &b, &c); D = pow(b, 2)/(4*pow(a,2))-c/a; if (D >= 0) { if (D == 0) { x = -b/(2*a); printf(”One solution X:%.2lf\n”, x); } else { x1 = -b/(2*a)+ sqrt(D); x2 = -b/(2*a)- sqrt(D); printf(”Two solutions X1:%.2lf X2:%.2lf\n”, x1, x2); } } else { }

display No solution

printf(”No solutions!\n”);





info(); answer=ask_again(); while(answer != ’n’ && answer != ’N’) { printf(”Input a b c with spaces:”); scanf(”%lf%lf%lf”, &a, &b, &c); D = pow(b, 2)/(4*pow(a,2))-c/a; if (D >= 0) { if (D == 0) { x = -b/(2*a); printf(”One solution X:%.2lf\n”, x); } else { x1 = -b/(2*a)+ sqrt(D); x2 = -b/(2*a)- sqrt(D); printf(”Two solutions X1:%.2lf X2:%.2lf\n”, x1, x2); } } else { printf(”No solutions!\n”); } answer=ask_again(); }

c:\windows\system\cool.dllProgram

THE END

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Examples Rules More examples