130: CISC Today's Class
Recap The Current Assignment Assignment Grades Handing In Assignments Do Loop Lab time, if time.
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R. Smith - University of St Thomas - Minnesota
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Recap
Problem solving with functions Side Effects Scope of Variables Assignment 4
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R. Smith - University of St Thomas - Minnesota
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Notes on the Assignment
READ the ASSIGNMENT!
You get full credit ONLY if you meet all requirements Declare all the required functions use others if you want. Functions should behave as described in the assignment Input/output should occur as described
Source code style: indenting and comments Use this style for each function!
Include the "function header" comment from the assignment Put all variable declarations together at start Comment every variable declaration Don't just repeat the variable names in the comment Comment every 2-8 lines; blanks set off those lines Indent to show control flow ONLY
R. Smith - University of St Thomas - Minnesota 3
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Homework Grading
Check plus check check minus - zero
Basically, means about A-B-C (or zero)
I post the grades on Blackboard
Homework grades are CP-CH-CM-or Z If you get extra credit, you might see a number there. Blackboard prints numbers when words aren't enough There should also be a running total of your current grade This can fluctuate wildly if you don't hand in homework
Comments on homework
Handwritten on paper copy Posted to Blackboard if you only e-mailed your work.
04/25/09
R. Smith - University of St Thomas - Minnesota
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Handing in C Homework
E-mail me the source code file (filename.c)
No spaces in the file name Include assignment number in file name Send as an Attachment
"Subject" Line of the E-Mail
ALWAYS include the course number CISC 130 When sending an assignment, include assignment number! When sending a question about class, say "Question about Class" or something like that (i.e. "Need help with ...") When 04/25/09 When sending an advisor question say "Advisor Question" R. Smith - University of St Thomas - Minnesota
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Finishing the Assignment
It is due at the end of the day Thursday We will work on it during Thursday Lab
MAYBE later in this hour, if time
I will be available Thursday afternoon IF people contact me and say they need me around
If you're still struggling by the end of Thursday lab, let me know
04/25/09
R. Smith - University of St Thomas - Minnesota
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Another thought about functions
When we use functions, things are out of order
The functions appear first Main is last. Functions are called in Main, or they are called in other functions
It's like a show with many different Each acts
act has its own script or music The players get their own scripts or music first Some acts are `one man shows' with one script Other acts have many players, scripts, music
Main is "the show"
It brings in the main acts ("functions") Some acts only happen when called on by other acts
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Does recursion make sense?
Problem: a calculation with repetition
Fibonacci = successive additions Factorial = successive multiplications Powers of two = successive multiplications
Is there a more obvious way? Yes, we can repeat statements until they pass an "if" like test
04/25/09
R. Smith - University of St Thomas - Minnesota
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Repeating, based on a test
We execute the first step
Collects and initializes some variables
Input X A=1
We execute the second step
Does the calculation Does bookkeeping to see if we're finished
A=A*2 X=X-1
True
We test to see if we should repeat the second step
We keep repeating until the test turns false
X > 0?
False
Once false, we stop repeating that step
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Print A
R. Smith - University of St Thomas - Minnesota
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The `do while' statement
Syntax:
do { statements ; } while ( expression );
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R. Smith - University of St Thomas - Minnesota
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From the Flowchart
X = getint(); A = 1; do { A = A * 2; X = X 1; while (X > 0); printf (" %d", A);
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Do-While example Example
Flowchart example Read a number X Calculate 2X Input controlled loop
Read in a number Repeat loop that many ti...