Assignment2.cpp

Assignment2.cpp

#include <iostream>
using namespace std;

float totalPrice, highestPrice, lowestPrice;
int highestIndex, lowestIndex;
int bookCount = 0;

int bookIds[1000];
string bookNames[1000];
float bookPrices[1000];

void showMenu();
void showSubmenu(int choice);

void showSubmenu(int choice) {
	system("cls"); // Clear Screen
	switch (choice) {
		case 1: {
			// Menu add book
			int bookId;
			string bookName;
			float bookPrice;
			cout << "Please input these information:"; cout << endl;
			cout << "    - ID: "; cin >> bookId; cout << endl;
			cout << "    - Name: "; cin >> bookName; cout << endl;
			cout << "    - Price: "; cin >> bookPrice; cout << endl;
			
			bookCount += 1;

			bookIds[bookCount] = bookId;
			bookNames[bookCount] = bookName;
			bookPrices[bookCount] = bookPrice;

			totalPrice += bookPrice;

			if (bookPrice < lowestPrice) {
				lowestIndex = bookCount;
				lowestPrice = bookPrice;
			} else if (bookPrice > highestPrice) {
				highestIndex = bookCount;
				highestPrice = bookPrice;
			}

			showMenu();

		}
		case 2: {
			int bookInputId;
			bool found = false;

			cout << "Please input Book's ID: ";
			cin >> bookInputId;
			for (int i = 1; i <= bookCount; i++) {
				if (bookIds[i] == bookInputId) {
					found = true;
					int bookIndex = i;
					cout << "Here is information about this book:" << endl;
					cout << "    - ID: " << bookIds[bookIndex] << endl;
					cout << "    - Name: " << bookNames[bookIndex] << endl;
					cout << "    - Price: " << bookPrices[bookIndex] << endl;
				}
			}
			if (!found) cout << endl << "There's no book has that ID!";
			showMenu();
		}
		case 3: {
			// Menu statistics
			int amountLower = 0, amountHigher = 0;
			float averagePrice = totalPrice / bookCount;
			for (int i = 1; i <= bookCount; i++) {
				amountLower += (bookPrices[i] > averagePrice) ? 1 : 0;
				amountHigher += (bookPrices[i] > averagePrice) ? 1 : 0;
			}
			cout << "Average price is: " << averagePrice << endl;
			cout << "There're " << amountHigher << " books has price higher than the average price." << endl;
			cout << ".... and " << amountLower << " books has price lower than the average price." << endl;
			cout << endl << endl;
			cout << "The most expensive book has ID: " << bookIds[highestIndex] << " with price: " << highestPrice << endl;
			cout << "The cheapest book has ID: " << bookIds[lowestIndex] << " with price: " << lowestPrice << endl;
			system("pause");
			showMenu();
		}
		case 4:
			// Quit
			exit(0);
			break;
		default:
			showMenu();
			break;
	}
}

void showMenu() {
	system("cls"); // Clear Screen
	cout << "Please choose an option:" << endl;
	string menu[] = { "1. Add book", "2. Check information", "3. Statistic", "4. Quit" };
	for (string line : menu) cout << line << endl;
	cout << endl << "Your choice is: ";
	int choice;
	cin >> choice;

	showSubmenu(choice);
}

int main() {
	showMenu();

	return 0;
}