Project 2: Fill ‘er up! Solution

File(s) to be submitted: gaspump.h, gaspump.cpp, proj2.cpp, makefile




Objectives: 1) Use classes; 2) Split interface and implementation into files; 3) Use an array of pointers to objects; 4) Instantiate objects using parameterized constructors; 5) Use objects in a client/driver function.




Project description:




In this assignment you will create a class representing a gasoline pump. The pump will maintain a running total of the amount of fuel dispensed and revenues collected. The driver program will simulate fuel demand for a number of vehicles.




Requirements:




Your program must be split into three files, the requirements for which are specified below:



The class interface, or declaration, file



Must be named gaspump.h



Must contain #include guards for GASPUMP_H
Class must be named GasPump
Will have these private members

A string containing the type of gas the gas pump holds
A double representing the amount of fuel on hand (in gallons)
A double representing the fuel pump’s capacity (in gallons)
A double that holds the price per gallon
A double representing the total amount of fuel dispensed (all purchases)
A double that stores the total amount of money collected (all purchases)
A bool that indicates whether the next customer should be turned away as fuel is replenished
A void function that replenishes the fuel pump’s tank when it runs out of fuel



Must have these public members



A single constructor with three parameters (in order): a standard string (std::string) that holds the type of gasoline in the pump, a double representing the maximum capacity of the tank in gallons, and a double for the price per gallon.



An inline accessor function that returns a standard string for the pump’s fuel type
An inline accessor function that returns a double for the pump’s fuel price per gallon
An inline accessor function that returns a double for the pump’s fuel on hand
An inline accessor function that returns the total amount of fuel dispensed (all purchases)



An inline accessor function that returns the total amount of revenue collected (all purchases)
A void function dispenseFuel, that controls the fueling of vehicles



A class implementation, or definition, file



Must be named gaspump.cpp
Will have the implementation for the following functions



Constructor – This function has three parameters that map directly to data members; it should also initialize the fuel quantity on hand to the maximum tank capacity (i.e., start at full capacity)
replenish – This function resets the fuel tank level to the maximum capacity.



dispenseFuel – This function is the heart of the class, and controls the fueling of a single vehicle. It accepts a pointer to a double (to the fueling outcome array), and a double that indicates the purchase amount desired by the vehicle. It uses the pointer to set the values in the 2-element array: actual purchase amount (element 0) and actual quantity of fuel dispensed to the vehicle (element 1). The amount of fuel a vehicle gets is one of the following: 1) the full amount requested by the vehicle (if it is available); or 2) the remaining amount in the tank (if the tank has less than the requested amount); or 3) Zero, if the vehicle is being turned away so the tank can be replenished.



It does this by




Converting the purchase amount to gallons of fuel.



Ensuring that it only dispenses fuel if the tank is not being replenished (in which case the customer is turned away)



Ensuring that the pump dispenses no more than the amount of fuel on hand. If the vehicle’s fuel demand exceeds the amount of fuel on hand, the vehicle gets all of the fuel on hand, and the next customer is turned away as the fuel is replenished.



Keeping track of fuel total dispensed
Keeping track of total revenue collected



A driver, or client, file



Must be named proj2.cpp
Reads input data from a file named gas.txt, that will be formatted as follows:
The first line is a random number seed (integer)
The second line is the number of vehicles to be run through the simulation



The 3rd through 5th lines represent individual gas pumps (one per line), composed of:

Gasoline type (string)
Tank capacity (double)
Cost per gallon (double)



Percentage of vehicles requiring this type of gas (double between 0 and 1) – Note: this field must sum to 1 across the three gas pump lines



Example line: Unleaded 100.0 2.00 0. 5 – Note that in this case, the percentage values in the other two lines must sum to 0.5



Instantiates an array of pointers to 3 GasPump objects, using data read from the input file.
Declares a 2-element double array that is passed to the dispenseFuel function to get the outcome of fueling



Sets the random number generator seed [using srand()] to the value read from the input file:
Creates a loop for the number of vehicles to be simulated - one vehicle per iteration:



Determine which pump the vehicle will fuel from, by drawing a random number between 0 and 1, [use ((double) rand() + 1) / RAND_MAX to prevent a divide by zero error] and comparing it against the “stacked” percentages read from the file, to select the pump pointer array index. Example:



Index
1.0






Fuel Type 1 Percentage (line 3): 0.3




0.7




Random draw 0.64 results








in selection of index 1 for
1
Fuel Type 2 Percentage (line 4): 0.6
the fuel type




0.1



Fuel Type 3 Percentage (line 5): 0.1






0.0
Determine the amount of money the vehicle wants to spend on fuel



Select random values from $30 to $55 in increments of $5, by drawing a random integer with rand, modding it by 6, multiplying the result by 5, and adding 30 to it.
Use the pointer at the index to invoke the dispenseFuel function in the appropriate pump



Output a single line containing the following (in order):



Vehicle #, fuel type, price per gallon, desired purchase amount, actual purchase amount, gallons dispensed, gallons remaining



Upon exiting the loop, output the total fuel dispensed and total revenue collected for each pump (in order)






Sample Output (with explanation) – This is the output from running with the provided sample input file. The format of your output MUST MATCH EXACTLY the output in this specification. DO NOT add any verbiage or information beyond what is called for.



































































































Test your program - Use different random number seeds, numbers of vehicles, prices, and tank capacities.



Code comments - Add the following comments to your code:



A section at the top of the source file(s) with the following identifying information:



Your Name

CSCI 3110-00X (your section #)

Project #X

Due: mm/dd/yy




Below your name add comments in each file that gives an overview of the program or class.



Place a one or two line comment above each function that summarizes the workings of the function.
5. Rubric




Requirement
Points Off
main: Input filename
-5




main: Data correctly read from file
-10




main: GasPump pointer array declaration and initialization
-10




main: Declaration of fueling outcome array
-5




main: Random number seeding
-5




main: Fuel pump selection
-5




main: Fuel purchase amount selection
-5




main: Invocation of functions through object
-5




main: All required output per vehicle
-10




main: Required final totals output
-5




GasPump: Constructor properly initializes objects
-5




GasPump: Accessors declared/defined per the specifications
-5




GasPump:dispenseFuel: Dispenses fuel and updates fueling outcome and totals
-10




GasPump:dispenseFuel: Sets up and invokes tank replenishment
-10




GasPump: Maintains totals for fuel dispensed and revenue collected
-5 (each)




GasPump:replenish: Correctly replenishes pump
-10




general: Does not compile (on ranger using Linux g++ compiler, and the provided makefile)
-25




general: Runtime crash
-25




general: Other
TBD