1. Psuedo Code

2. Pseudo Code Pseudo = Fake Code = Fancy computer stuff
A way to organize your program before coding it

4. General Guidelines Input Output Steps in between Not Language Specific
Only you need to understand it
Should not compile

5. Steps to Pseudo Coding Step 1: Outline Step 2: Actual Pseudo Code
Very General, Inputs to outputs
Little computer code used
Short and to the point
Step 2: Actual Pseudo Code
More line by line
Focus on variable storage and functions

6. ToolBox Variables (int, float, char, string) Arrays, dict/hash tablesIf
If-Else
While loop
For loop
Functions
The Google

7. Problem 1 Gregg keeps getting on your computer and running your code
Write a program that asks for the users name
If its Gregg tell him to get back to work
Input: User’s name
Output: Chiding Statement

8. Problem 1: Outline Solution
Load in a user name from the keyboard
Check if that name is Gregg
If it is Gregg, say something

9. Problem 1: Pseudo Code
User Name = userInput(stuff) If User Name is Gregg Print Chiding Statement to Snoop Gregg Else Print You do You!

10. Class Problem 1
Write a program that takes in a number from a user and tells them if it is Divisible by 11
Input = User Number
Output = Printed statement on divisibility
Hint: Mod (%) gives the remainder
5 Mod 2 = 1

11. Class Problem 1: Outline Solution
Load in a number from the user
See if that number is divisible by 11
If it is tell them
If it is not, tell them

12. Class Problem 1: Pseudo Code Solution
Number = userInput(stuff) If Number Mod 11 is 0 Print Affirmative Statement Else Print Negative Statement

13. Problem 2
Write a program that takes in a number from a user and tells them if it is Divisible by 11
But keep asking until the user enters the number 0

14. Problem 2: Pseudo Code Why will this not work?
While(Number is not 0) Number = userInput(stuff) If Number Mod 11 is 0 Print Affirmative Statement Else Print Negative Statement
Why will this not work?

15. Class Problem 2: Pseudo Code
Number = not 0 While(Number is not 0) Number = userInput(stuff) If Number Mod 11 is 0 Print Affirmative Statement Else Print Negative Statement

16. Problem 3
You are given a DNA Sequence and have to report how many times the Motif CAT appears
Input = DNA Sequence (GATTACA), CAT
Output = CAT Count
Hint1: A string is really just as an array/list of characters
[‘G’,’A’,’T’,’T’,’A’,’C’,’A’]
Hint2: you can take a slice out of an array
Array[2 to 4]

17. Problem 3: Outline Load DNA Sequence and CAT into variables
make a motif counter
Iterate through DNA sequence
Pull out sets of three letters and compare to CAT
If we find CAT increment the counter
Report the final count

18. Visual Representation
G A T T A C A

19. Problem 3: Pseudo Code
Motif = CAT DNASeq = loadFile(InputDNA) CAT_Count = 0 For i in DNASeq Range – 2 if(DNASeq i to DNASeq i+2 is CAT) CAT_Count + 1 Print CAT_Count

20. Class Problem 3
You are given a DNA sequence and have to determine its GC content (percentage)
Input = DNA sequence (GATTACA)
Output = GC content
Hint: Loops are your friend

21. Class Problem 3: Outline
Load in sequence
Set up a GC counter
Loop through sequence
Compare every letter to G or C
Determine total nucleotide count
Do appropriate math to get percentage

22. Class Problem 3: Pseudo Code
DNASeq = loadFile(InputDNA) GC_Count = 0 For Letter in DNASeq if Letter is G or C GC_Count + 1 DNALength = length(DNASeq) GC = GC_Count/DNALength X 100% Print GC

23. Real Code

24. Better Real Code

25. Parting Lessons Inputs Outputs Toolbox Take Your Time
Only you have to understand your pseudo code

26. Class Problem 4
You need a program that will take in a DNA sequence from a user and return the the reverse complement RNA sequence
Input: DNA sequence
Output: RNA Sequence
Hint 1: You can reverse a list, or you can loop through a list backwards
Hint2: Figuring out the complement can be done with a series of if statements

27. Class Problem 4: Outline
Load in DNA sequence
Loop through the sequence from back to front
Check identity of each letter, add its complement to new string
Remember RNA has U, not T

28. Class Problem 4: Pseudo Code
DNASeq = userInput(stuff)
RNASeq = empty list
Seq Length = length(DNASeq)
For I in range 0 to seq Length
Index = length(DNASeq) – I
If DNASeq[index] is G
RNASeq + C
Else if DNASeq[index] is A
RNASeq + U
… and so on

29. Real Code!