Tutorial 2: Flowcharts, Modularity,
Numbers

NOTE

In this tutorial we will assume that we are drawing flowcharts by hand on paper. It's better for cementing the concepts/skills because we don't get distracted by learning an application.  BUT, there are lots of tools to learn to draw beautiful flowcharts. One that might be in your repertoire (or soon will be) is MIRO

Platform: MIRO

If you are so inclined...

https://bit.ly/1339F21-TU02

Go to our shared whiteboard here

Exercises

Q1 text2fc

Show Solution

Draw the flowchart: if the light is green, go, otherwise stop.

Q1 text2fc

Next

Draw the flowchart: if the light is green, go, otherwise stop

green?

go

YES

NO

stop

Q2 text2fc

Show Solution

Draw the flowchart: if the light is green, go, otherwise if the light is red, stop.

Q2 text2fc

Next

Draw the flowchart: if the light is green, go, otherwise if the light is red, stop.

green?

red?

go

YES

NO

stop

YES

NO

Click on forward arrow to reveal solution

How to Convert Decimal to Binary (dec2bin)

521 decimal = ? in binary
521 divided by 2 = 260 remainder of 1
260 divided by 2 = 130 remainder of 0
130 divided by 2 =  65 remainder of 0
 65 divided by 2 =  32 remainder of 1
 32 divided by 2 =  16 remainder of 0
 16 divided by 2 =   8 remainder of 0
  8 divided by 2 =   4 remainder of 0
  4 divided by 2 =   2 remainder of 0
  2 divided by 2 =   1 remainder of 0
  1 divided by 2 =   0 remainder of 1

Click FORWARD to see step by step computation

How to Convert Decimal to Binary (dec2bin)

521 decimal = ? in binary
521 divided by 2 = 260 remainder of 1
260 divided by 2 = 130 remainder of 0
130 divided by 2 =  65 remainder of 0
 65 divided by 2 =  32 remainder of 1
 32 divided by 2 =  16 remainder of 0
 16 divided by 2 =   8 remainder of 0
  8 divided by 2 =   4 remainder of 0
  4 divided by 2 =   2 remainder of 0
  2 divided by 2 =   1 remainder of 0
  1 divided by 2 =   0 remainder of 1
1
0
0
1
1
0
0
0
0
0

How to Convert Decimal to Binary (dec2bin)

521 decimal = ? in binary
1
0
0
1
1
0
0
0
0
0
521 divided by 2 = 260 remainder of 1
260 divided by 2 = 130 remainder of 0
130 divided by 2 =  65 remainder of 0
 65 divided by 2 =  32 remainder of 1
 32 divided by 2 =  16 remainder of 0
 16 divided by 2 =   8 remainder of 0
  8 divided by 2 =   4 remainder of 0
  4 divided by 2 =   2 remainder of 0
  2 divided by 2 =   1 remainder of 0
  1 divided by 2 =   0 remainder of 1

Q1021.

Consider this algorithm for converting a number in base 10 to its base 2 representation:

Proceed Stepwise: (1) Pseudocode; (2) Outside; (3) Inside

Divide the number by two recording both the quotient and the remainder.

Write the remainder down

Take the quotient and divide it by two, recording both the quotient and the remainder.

Write the remainder to the LEFT of what's already written.

Repeat until the quotient reaches zero.

Q1021.

                Consider this algorithm for converting a number in base 10 to its base 2 representation:

Proceed Stepwise: (1) Pseudocode; (2) Outside; (3) Inside

Divide the number by two recording both the quotient and the remainder.

Write the remainder down

Take the quotient and divide it by two, recording both the quotient and the remainder.

Write the remainder to the LEFT of what's already written.

Repeat until the quotient reaches zero.

N is our number
Q = N / 2
R = remainder
Write R
Treat Q as the new N
If Q not 0, repeat


repeat
   Q = N / 2
   Write remainder
   N = Q
until Q = 0

Q1021.

                Consider this algorithm for converting a number in base 10 to its base 2 representation:

Proceed Stepwise: (1) Pseudocode; (2) Outside; (3) Inside

Divide the number by two recording both the quotient and the remainder.

Write the remainder down

Take the quotient and divide it by two, recording both the quotient and the remainder.

Write the remainder to the LEFT of what's already written.

Repeat until the quotient reaches zero.

Fix Filho's Wikipedia Flowchart

Fix Filho's Wikipedia Flowchart

edit
if anyone modifies
   engage in edit war
else
   get on with your life.

 

make edit
repeat
    engage
until agreement

 

repeat
    edit page
until people stop changing it

 

edit page
if anyone modifies
   while you don't accept mod
      repeat
         discuss
      until agree
   make edit

 

Numbers

Problems

DEC2BIN

BIN2DEC

BIN2HEX

HEX2DEC

ASCII2TEXT

HEX2ASCII2TEXT

What is 43910 in binary?

What is 43910 in binary?

439 / 2 = 219 R1
219 / 2 = 109 R1
109 / 2 =  54 R1
 54 / 2 =  27 R0
 27 / 2 =  13 R1
 13 / 2 =   6 R1
  6 / 2 =   3 R0
  3 / 2 =   1 R1
  1 / 2 =   0 R1

110110111

256+128+32+16+4+2+1=439

What is 11011011012 in decimal?

512+256+64+32+8+4+1=877

What is 3067 in decimal?

3 x 49 + 6 = 153

In what base is 4010written as 28?

To convert 28 base A to decimal we would compute 2 x A + 8 = 40. Solving for A yields 16.

You can be "29" many times in life. What is 29 in these bases?

2913 = ?10

2921 = ?10

2932 = ?10

298 = ?10

2929 = ?10

3510

5110

7310

2510

6710

ASCII

53 74 65 70 77 69 73 65 20 72 65 66 69 6e 65 6d 65 6e 74 20 69 73 20 70 6f 77 65 72 66 75 6c 2e

Use the ASCII table below to decode this message

Stepwise refinement is powerful.

Click for Solution

ASCII

4b 65 65 70 20 43 61 6c 6d 20 61 6e 64 20 44 65 66 65 72 20 44 65 74 61 69 6c 2e

Use the ASCII table below to decode this message

Keep Calm and Defer Detail.

Click for Solution

Use the ASCII to text converter on the next slide to convert the message below:

3c 70 3e 41 6e 73 77 65 72 20 63 6f 72 72 65 63 74 65 64 20 66 6f 72 20 66 69 72 73 74 20 62 6c 61 6e 6b 20 69 6e 20 71 75 65 73 74 69 6f 6e 26 6e 62 73 70 3b 3c 2f 70 3e 0a 3c 70 3e 3c 69 6d 67 20 73 72 63 3d 22 68 74 74 70 73 3a 2f 2f 71 2e 75 74 6f 72 6f 6e 74 6f 2e 63 61 2f 63 6f 75 72 73 65 73 2f 32 32 39 30 31 34 2f 66 69 6c 65 73 2f 31 35 39 37 32 33 31 39 2f 70 72 65 76 69 65 77 22 20 61 6c 74 3d 22 73 63 72 65 65 6e 73 68 6f 74 20 6f 66 20 70 72 6f 62 6c 65 6d 20 73 65 74 20 71 75 65 73 74 69 6f 6e 20 31 31 20 73 68 6f 77 69 6e 67 20 77 68 65 72 65 20 61 6e 73 77 65 72 20 68 61 73 20 62 65 65 6e 20 63 6f 72 72 65 63 74 65 64 22 20 77 69 64 74 68 3d 22 33 32 30 22 20 68 65 69 67 68 74 3d 22 37 32 22 20 2f 3e 3c 2f 70 3e

Use the TEXT2ASCII converter on the next slide to convert the message below:

AD0BE CODE 1CED A BAD 1DEA

You can read all about ASCII at CSUSB and at SparkFun.

Use the URL escape/unescape on the next slide to...

HTTPS%3A//A.COM%3FTITLE%3DWHY%20CAN%27T%20I%20HAVE%20NICE%20THINGS

...decode 

https://a.com?title="the title is what i put in quotation marks"

...encode

Binary Coded Decimal (BCD)

See Wikipedia, "Binary Coded Decimal"

Binary Coded Decimal (BCD)

See Wikipedia, "Binary Coded Decimal"

What is the BCD version of

101

7

42

What is the decimal equivalent of these BCD values?

0101

1000 0100

1100

0001 0000 0001

0111

0100 0010

5

84

invalid*

 *the unused, don't care-states are named pseudo-tetrad(e)s, pseudo-decimals[ or pseudo-decimal digits. (wikipedia)

The top floors of this skyscraper contain a message. What is it?

OUT TAKES

Example 1

If today is Tuesday, we must be in Belgium

Tuesday?

Belgium

YES

?

Example 2

DO A. 
IF B, 
   DO C, 
   otherwise DO D. 
DO E. 
DO F.

B

A

E

F

C

D

YES

NO

IF B

DO C

OTHERWISE D

IF B, 
   DO C, 
   otherwise DO D.

Example 2

DO A. 
IF B, 
   DO C, 
   otherwise DO D. 
DO E. 
DO F.

B

A

E

F

C

D

YES

NO

IF B

DO C

OTHERWISE D

IF B, 
   DO C, 
   otherwise DO D.

New Concept: Flowchart for Repetition

WHILE A DO B

A?

B

YES

NO

SINGLE EXIT POINT

SINGLE ENTRY POINT

New Concept: Flowchart for Repetition

REPEAT B UNTIL A

A?

B

SINGLE EXIT POINT

SINGLE ENTRY POINT

NO

YES

Tutorial 2: Flowcharts

By Dan Ryan

Tutorial 2: Flowcharts

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