//4.35
#include <iostream>

using namespace std;

double factorial (double num) {
    double result{1};
    double counter{0};
    while (counter < num) {
        result = result * (num-counter);
        counter++;
    }
    return result;
}

double calculateE (double accuracy) {
    double e{1};
    double counter{1};
    while (counter < accuracy+1) {
        e = e + 1/(factorial(counter));
        counter++;
    }
    return(e);
}


double power (double num, double power) {
    double counter{0};
    double result{1};
    while (counter < power) {
        result = result*num;
        counter++;
    }
    return result;

}

double calculateEX (double accuracy, double x) {
    double e{1};
    double counter{1};
    while (counter < accuracy+1) {
        e = e + power(x,counter)/(factorial(counter));
        counter++;
    }
    return(e);
}

int main()
{
    double num{0};
    cout << "Please input a number to calculate its factorial: " << endl;
    cin >> num;
    cout << factorial(num) << endl;
    cout << "Please input a degree of accuracy for our e calculation " << endl;
    cin >> num;
    cout << "e approx =" << calculateE(num) << endl;
    cout << "Please input e^x for what value of x?" << endl;
    cin >> num;
    cout << "e^" << num << "= " << calculateEX(10,num) << endl;
    return 0;
}

//4.26

#include <iostream>

using namespace std;


void solidline(int length) {
    int counter{0};
    while (counter < length) {
        cout << "*";
        counter++;
    }
    cout << endl;
}

void hollowline(int length) {
    int counter{0};
    while (counter < length) {
        if (counter == 0 || counter == length-1) {
          cout << "*";
        }
        else { cout << " ";}
        counter++;
    }
    cout << endl;
}

int main() {
    int sideLength{0};
    int counter{0};
    cout << "Please enter a side length for your square." << endl;
    cin >> sideLength;
    solidline(sideLength);
    while (counter < sideLength-2) {
      hollowline(sideLength);
      counter++;
    }
    solidline(sideLength);
    return 0;
}

//4.17
#include <iostream>

using namespace std;

int main()
{
    int counter{0};
    int inputNum{0};
    int currentLargest{0};
    while (counter < 10) {
        cout << "Please enter a number." << endl;
        cin >> inputNum;
        if (inputNum > currentLargest)
        {
            currentLargest = inputNum;
        }
        counter++;
    }
    cout << "The largest number was: " << currentLargest << endl;
    return 0;
}

//4.13
#include <iostream>

using namespace std;

int main()
{
    string quit{"moo"};
    int miles{0};
    int gallons{0};
    int ttlMiles{0};
    int ttlGallons{0};
    while (quit != "n") {
        cout << "Please enter the miles driven: " << endl;
        cin >> miles;
        cout << "Please enter the gallons used: " << endl;
        cin >> gallons;
        cout << "MPG this trip: " << miles / gallons << endl;
        ttlMiles = ttlMiles + miles;
        ttlGallons = ttlGallons + gallons;
        cout << "Total MPG so far: " << ttlMiles / ttlGallons << endl;
        cout << "Would you like to continue entering data? (y/n)" << endl;
        cin >> quit;
    }
    return 0;
}

//4.36 (main)
#include <iostream>
#include "account.h";
#include <iomanip>
using namespace std;

int main()
{
    Account test1("Jones", 400.00);
    cout.precision(2);
    cout << "Hello world!" << endl;
    cout << "Current balance is.... " << fixed << test1.getBalance() << endl;
    cout << test1.withdraw(100.00) << endl;
    cout << fixed << test1.getBalance();
    return 0;
}

//4.36 (header)
#include <string>
#include <iostream>

class Account {
public:
    Account(std::string accountName, double initialBalance)
        : name{accountName} {

        if (initialBalance > 0) {
            balance = initialBalance;
    }
    }
    void deposit(double depositAmount) {
    if (depositAmount > 0) {
        balance = balance + depositAmount;
    }
    }

    double getBalance() const {
    return balance;
    }

    void setName(std::string accountName) {
    name = accountName;
    }

    std::string getName() const {
    return name;
    }

    std::string withdraw(double withdrawAmount) {
    if (withdrawAmount > balance) {
        return("You do not have enough money in your account to do that.");
    }
    else {
        balance = balance - withdrawAmount;
        return("Money withdrawn succesfully.");
    }
    }

private:
    std::string name;
    double balance{0};
};