C-programing- Note 12 - Note 12 PDF

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Note 12...

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CSCI 1320 C Programming

Class Notes (10/13/2020)

Last time: Basics of Looping Today: Review for the midterm exam Time: Thursday, Oct. 15 (8:30am-9:50am) Format: Take home exam The midterm exam questions will be posted in the Blackboard discussion board by 8:30am this Thursday. Send your answers as a Word file to [email protected]. Advice: Make sure you fully understand everything covered in the class notes. 

Components of a computer system: cpu (arithmetic and logic processing), primary memory (RAM), secondary/auxiliary storage (e.g., disks), input devices, output devices

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Memory buffer?

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The process of solving a problem (from the given task/problem to the final product/solution)

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The process of creating a working program (from the editor to the final product)

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Binary numbering system, hexadecimal system

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if else

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nested if else statements

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program design using flowcharts

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program design using pseudocodes

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how to define a function

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how to use a function in a program

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how to trace a given function

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how to pass data when calling a function: parameter passing by values vs parameter passing by references/pointers

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basic looping (using flowchart and pseudocode)

Type of questions: problem-solving kinds of questions

e.g., - trace a function call, trace a flowchart or a pseudocode, - define a function, or design a solution using a pseudocode or flowchart, - converting a pseudocode to a flowchart or a c code, or vice versa

A loop in a program consists of a block of statements that are continually executed until certain condition becomes false. That is, when the looping condition remains true, the loop will continue.

Begin

Components of a loop: 1. Initialization of the looping variable(s)

a = 100 2. The looping condition b = 222

False a > 0 && a < b True

Print “Bye ”

Print a, b 3. The body of the loop a a /2

End

4. Change(s) of the looping variable(s) in the body of the loop b b-a

Exercise: Write the flowchart as a C program, and test it.

Exercise: Trace this program. a 100 50

b 200 150

Screen Output 100 200 50 150

25 12 6 3 1 0  

125 25 125 113 12 113 107 6 107 104 3 104 103 1 103 103 Bye Each row in the above tracing table is called an iteration of the loop. && means the logical ‘and’.

NOTE: An int divided by another int produces an int (i.e., an integer division). 25/2  12 1/2  0 

An infinite loop is a loop that will never end, because the looping condition is always true.

Exercise: Design a function called printNumbers( ) that takes a positive integer as the parameter, and then print all the numbers 1, 2, …, up to the given integer. For example, printNumbers(5) will print out 1 2 3 4 5, while printNumbers(10) will print out 1 2 3 4 5 6 7 8 9 10. Draw a flowchart to show your design of such a function. printNumbers (N): 1. Initialization of the looping variable(s), commonly called the iterator Let i =1 2. The looping condition i b, then go to step 7. Add a to result. Add a to i. Go to step 3. return result

Next Time: The midterm exam...