Solution

// Programmer: Clayton Price

// File: hw3.cpp

// Description: This file contains the main function for the program that will

// compute a ocular prescription for Milhouse

#include <iostream>

using namespace std;

int main()

{

//constants for the program

const string CODE_PART1_OPT1 = "P"; //first parts of code

const string CODE_PART1_OPT2 = "B";

const string CODE_PART1_OPT3 = "C";

const short CODE_PART1_OPT1MAX = 5; //limits for part 1

const short CODE_PART1_OPT2MAX = 10;

const short MIN_CORNEA = 1; //limits for cornea measure

const short MAX_CORNEA = 20;

const long MAGIC_FORMULA_CONST1 = 7919; //constants for the magic

const long MAGIC_FORMULA_CONST2 = 104729; // formula

const long MAGIC_FORMULA_CONST3 = 101;

const long MAGIC_FORMULA_CONST4 = 150;

const short CODE_PART2_OPT1MIN = 150; //range limits for figuring

const short CODE_PART2_OPT1MAX = 200; // part 2

const short CODE_PART2_OPT2MIN = 201;

const short CODE_PART2_OPT2MAX = 250;

const string CODE_PART2_OPT1 = "iN"; //second parts of code

const string CODE_PART2_OPT2 = "Li";

const string CODE_PART3_OPT1 = "N"; //third parts of code

const string CODE_PART3_OPT2 = "Ke";

const string CODE_PART3_OPT3 = "P";

const string CODE_PART4_OPT1 = "d"; //fourth parts of code

const string CODE_PART4_OPT2 = "ky";

const string CODE_PART4_OPT3 = "h";

const string CODE_PART4_OPT4 = "ye";

const short MAX_SNELLEN_LINE = 9; //number of lines on a snellen

//variables

string part1; //parts of the code

string part2;

string part3;

string part4;

string name; //user's name for friendliness

long start;

long magic_form_part1, magic_form_part2;

float magic_formula;

short cornea;

short snellen_error; //line num for first error on snellen chart

// input info from user and compute code **********

cout<<"\n\n\n\tVISION PRESCRIPTIFIER"<<endl<<endl;

cout<<"Please enter your name: ";

cin>>name;

cout<<"OK, "<<name<<", now measure your cornea and enter here: ";

cin>>cornea;

while (cornea < MIN_CORNEA || cornea > MAX_CORNEA)

{

cout<<"\tUnacceptable measure. Enter again: ";

cin>>cornea;

}

// now cornea between MIN AND MAX cornea measures

// figuring part 1 of code***********************

if (cornea < CODE_PART1_OPT1MAX)

part1 = CODE_PART1_OPT1;

else if (cornea < CODE_PART1_OPT2MAX)

part1 = CODE_PART1_OPT2;

else

part1 = CODE_PART1_OPT3;

// figuring part 2 of code***********************

// computing magic formula values

if (part1 == CODE_PART1_OPT1)

start = 1;

else if (part1 == CODE_PART1_OPT2)

start = 2;

else

start = 3;

magic_form_part1 = (start * MAGIC_FORMULA_CONST1 + MAGIC_FORMULA_CONST2) %

MAGIC_FORMULA_CONST3 + MAGIC_FORMULA_CONST4;

start = magic_form_part1;

magic_form_part2 = (start * MAGIC_FORMULA_CONST1 + MAGIC_FORMULA_CONST2) %

MAGIC_FORMULA_CONST3 + MAGIC_FORMULA_CONST4;

magic_formula = (magic_form_part1 + magic_form_part2)/2.0;

if (CODE_PART2_OPT1MIN <= magic_formula

&& magic_formula <= CODE_PART2_OPT1MAX)

part2 = CODE_PART2_OPT1;

else if (CODE_PART2_OPT2MIN <= magic_formula

&& magic_formula <= CODE_PART2_OPT2MAX)

part2 = CODE_PART2_OPT2;

// now for part 3 of the code **********************

do

{

cout<<"Please enter the upper-most line of Snellen chart with error: ";

cin>>snellen_error;

} while ( snellen_error < 1 || snellen_error > MAX_SNELLEN_LINE);

if (snellen_error == 1)

part3 = CODE_PART3_OPT1;

else if (snellen_error == 2)

part3 = CODE_PART3_OPT2;

else

part3 = CODE_PART3_OPT3;

// and part 4 of the code *********************************

if ((part1 == CODE_PART1_OPT1 || part1 == CODE_PART1_OPT2) &&

snellen_error == 1)

part4 = CODE_PART4_OPT1;

else if (part1 == CODE_PART1_OPT3 && snellen_error == 1)

part4 = CODE_PART4_OPT2;

else if (part2 == CODE_PART2_OPT1 && snellen_error >= 3)

part4 = CODE_PART4_OPT3;

else

part4 = CODE_PART4_OPT4;

// output of code ******************************************

cout<<endl<<name<<", ok, your code is: "<<part1<<part2<<part3<<part4

<<endl;

cout<<"Well, good luck earthman witht he lifestyle......"<<endl;

return 0;

}