Program #2

Algorithm for Parking at PSU

Understanding the Assignment

You will be writing a program to find out how much someone at PSU might be spending on Parking

Help the user figure out if they should…Buy a parking permitPark on the street (at a meter)Park in a pay lot (like Smart Park)

Cost of Parking….

I looked up parking rates for Winter 2009 and this is what I found…A term long pass at PSU (11 weeks) is $279Meters on the street are $1.25 per hourSmart parking depends on the number of

hours there.For 4 hours or less it is $1.25 per hourFor more than 4 hours it is $3 per hourMost lots have a maximum charge (e.g., $11)

Cost of Parking….

So, although we know what these rates are…right now…They are subject to change If we “hard code” these numbers into our

program, our program would never work for another term or another University or situation

So, we will use variables instead!

Data We will Need from User….

How many days they park downtownHow many hours (during the day) per day

on averagePrice of the PSU term long parking passPrice of the meters per hourPrice of short term parking at a Parking lotPrice of long term parking at a Parking lotMaximum price per day at a Parking lot

Some of the Variables….

This means we will need variables for at least:Number of days parking downtownAverage number of hours per dayPrice of the PSU term long parking passPrice of the meters per hourPrice of short term parking at a Parking lotPrice of long term parking at a Parking lotMaximum price per day at a Parking lot

Before we start the algorithm….

Before we start the algorithm, I have some hints and suggestionsStart small. Do one piece and once it works

then build upon itSo, first just input the price for parking at the

PSU lots (e.g., $279 for 12 weeks) and compute the monthly rate. Display this

Once that works, then move on to calculating the price at a meter! And, so on.

Major Tasks of the Algorithm

The Major Tasks of the Algorithm are:Welcome the UserGet the Data from the User

Prompt, Input, Echo the data for each itemCalculate the Monthly rateDisplay the ResultsDisplay a Termination Message

Just for PSU Parking

So, let’s look at a detailed algorithm for just calculating the price for parking at PSU Welcome the User (plan what you want to say)

Get the Price of parking for a term at PSUPrompt, Read, and Echo each

Prompt: Please enter the cost of buying a permit at PSU Read in the cost (using cin) Echo the cost (using cout)

Just for PSU Parking

Calculate the Monthly rateA term is 11 weeks long (for example)Divide the cost by 11.0 (using floats!)Multiply the answer by 4 (number of weeks in a

month) Cost per month = (Term Rate Divided by 11.0 ) times 4

Display the Results (using cout) “ Your cost at PSU parking lots will be $ “ …

Display a Termination MessagePlan what you want to say here

Add in the Price for Meters!

So, now let’s expand the algorithm to include the price of metersWelcome the User (plan what you want to say)

Get the Number of Days, Average Number of Hours, Price of parking at a meter

Prompt, Read, and Echo each Prompt: Please enter the number of days that you park

per week Read in the number of days (using cin) Echo the number of days (using cout)

Parking at a Meter

Prompt: Please enter the average number of hours you park Read in the number of hours (using cin) Echo the number of hours (using cout)

Prompt: Please enter the cost of parking at a meter Read in the cost (using cin) Echo the cost (using cout)

Parking at a Meter

Calculate the Monthly rate for a meterMultiply the cost of a meter by the number of hours

you park per day Multiply this by the number of days per weekMultiply this by 4

Cost per month = Meter Cost x hours per day x days per week x 4

Display the Results (using cout) “ Your approximate cost of street parking will be $ “

Display a Termination MessagePlan what you want to say here

Just for PSU Parking

Now, add this, piece by piece into your C++ program (maybe name it something else)

Enter it with an editor (like pico) in your cs161 directory

Save it as prog2b.cpp When you are back at the Unix prompt type:

g++ prog2b.cppNow, you can run the program (once you get

out all of the errors by typing .\a.out

Using a Parking lot (Smart Park)

So, if you are going for the extra credit, let’s keep going and add in the ability to park at a parking lot (other than PSU)

The new data we need to read in is:Get the price of short term parking, price of long

term parking, maximum price per dayPrompt, Read, and Echo each

Prompt: Please enter the short term, long term and maximum prices

Read in all three (e.g., using 3 cin statements) Echo the all three (using cout)

Parking at Smart Park

Calculate the Monthly rate for Smart Park If the number of hours per day is less than or equal

to 4, Cost = number of hours * number of days * short term cost

Otherwise if the number of hours times the long term rate is larger than the maximum parking amount,

Cost = number of days * maximum cost per day

Otherwise, Cost = number of hours * number of days * long term cost

Believe it or not, we are done!

Now, add this, piece by piece into your C++ program (maybe name it something else)

Enter it with an editor (like pico) in your cs161 directory

Save it as prog2c.cpp When you are back at the Unix prompt type:

g++ prog2c.cppGet the typos out by re-editing…and run it!

.\a.out