feat(Week03): Add solution to first exercise

7 files changed, 366 insertions, 0 deletions

diff --git a/Week03/Exercise01/Product.cpp b/Week03/Exercise01/Product.cpp
new file mode 100644
index 0000000..1bfa66e
--- /dev/null
+++ b/Week03/Exercise01/Product.cpp
@@ -0,0 +1,33 @@
+#include <iostream>
+#include <cstring>
+#include "Product.h"
+
+void ProductArray::add(const Product& product) {
+	if (count >= allocated) {
+		std::cout << "No more products are allowed!" << std::endl;
+		return;
+	}
+
+	products[count++] = product;
+}
+
+Product* ProductArray::find(char* username) {
+	for (unsigned i = 0; i < count; ++i)
+		if (strcmp(username, products[i].name) == 0)
+			return &products[i];
+	return nullptr;
+}
+
+ProductArray newProductArray(unsigned allocatedSize) {
+	ProductArray pa;
+	pa.products = new Product[allocatedSize];
+	pa.count = 0;
+	pa.allocated = allocatedSize;
+	return pa;
+}
+
+void deleteProductArray(ProductArray& pa) {
+	delete[] pa.products;
+	pa.products = nullptr;
+	pa.count = pa.allocated = 0;
+}
diff --git a/Week03/Exercise01/Product.h b/Week03/Exercise01/Product.h
new file mode 100644
index 0000000..6707bc1
--- /dev/null
+++ b/Week03/Exercise01/Product.h
@@ -0,0 +1,22 @@
+#ifndef _PRODUCT
+#define _PRODUCT
+
+struct Product {
+	char name[256];
+	unsigned count;
+	double price;
+};
+
+struct ProductArray {
+	Product* products;
+	unsigned count;
+	unsigned allocated;
+
+	void add(const Product& product);
+	Product* find(char* name);
+};
+
+ProductArray newProductArray(unsigned allocatedSize);
+void deleteProductArray(ProductArray& ua);
+
+#endif
diff --git a/Week03/Exercise01/Shop.cpp b/Week03/Exercise01/Shop.cpp
new file mode 100644
index 0000000..ce92d25
--- /dev/null
+++ b/Week03/Exercise01/Shop.cpp
@@ -0,0 +1,213 @@
+#include <iostream>
+#include <cstring>
+#include "Shop.h"
+
+void readUsername(char* str, unsigned length) {
+	std::cout << "Username: ";
+	std::cin.getline(str, length);
+}
+
+void readPassword(char* str, unsigned length) {
+	std::cout << "Password: ";
+	std::cin.getline(str, length);
+}
+
+void readName(char* str, unsigned length) {
+	std::cout << "Name: ";
+	std::cin.getline(str, length);
+}
+
+void Shop::runCommand(char command) {
+	switch (command) {
+		case 'l':
+			if (loggedInUser == nullptr) {
+				User temp;
+				readUsername(temp.name, sizeof(temp.name) / sizeof(*temp.name));
+
+				User* registeredUser = users.find(temp.name);
+
+				if (registeredUser == nullptr) {
+					std::cout << "User '" << temp.name << "' does not exist!" << std::endl;
+					return;
+				}
+
+				readPassword(temp.password, sizeof(temp.password) / sizeof(*temp.password));
+
+				if (strcmp(registeredUser->password, temp.password) != 0) {
+					std::cout << "Incorrect password!" << std::endl;
+					return;
+				}
+
+				loggedInUser = registeredUser;
+				std::cout << "Successfull login!" << std::endl;
+			}
+			break;
+
+		case 'r':
+			if (loggedInUser == nullptr) {
+				User temp;
+				temp.isAdmin = false;
+				readUsername(temp.name, sizeof(temp.name) / sizeof(*temp.name));
+
+				User* registeredUser = users.find(temp.name);
+
+				if (registeredUser != nullptr) {
+					std::cout << "User '" << temp.name << "' is already registered!" << std::endl;
+					return;
+				}
+
+				readPassword(temp.password, sizeof(temp.password) / sizeof(*temp.password));
+
+				users.add(temp);
+				std::cout << "Successfully registered user '" << temp.name << "'!" << std::endl;
+			}
+			break;
+
+		case 'p':
+			if (products.count > 0) {
+				for (unsigned i = 0; i < products.count; ++i)
+					std::cout << products.products[i].name << ' '
+					          << products.products[i].count << ' '
+					          << products.products[i].price << std::endl;
+			}
+			else {
+				std::cout << "No products!" << std::endl;
+			}
+			break;
+
+		case 'e':
+			if (loggedInUser != nullptr) {
+				loggedInUser = nullptr;
+				std::cout << "Logged out!" << std::endl;
+			}
+			break;
+
+		case 'b':
+			if (loggedInUser != nullptr) {
+				unsigned N;
+
+				std::cout << "Number of products: ";
+				std::cin >> N;
+				std::cin.ignore();
+
+				Product** shoppingCartProducts = new Product*[N];
+				unsigned* shoppingCartCounts = new unsigned[N];
+				unsigned cartItems = 0;
+
+				for (unsigned i = 0; i < N; ++i) {
+					Product temp;
+
+					readName(temp.name, sizeof(temp.name) / sizeof(*temp.name));
+
+					Product* storedProduct = products.find(temp.name);
+					if (storedProduct == nullptr) {
+						std::cout << "Invalid product name!" << std::endl;
+						delete[] shoppingCartProducts;
+						delete[] shoppingCartCounts;
+						return;
+					}
+
+					std::cout << "Quantity: ";
+					std::cin >> temp.count;
+					std::cin.ignore();
+
+					if (temp.count > storedProduct->count) {
+						std::cout << "Invalid quantity!" << std::endl;
+						delete[] shoppingCartProducts;
+						delete[] shoppingCartCounts;
+						return;
+					}
+
+					shoppingCartProducts[cartItems] = storedProduct;
+					shoppingCartCounts[cartItems++] = temp.count;
+				}
+
+				double total = 0.0;
+				for (unsigned i = 0; i < N; ++i) {
+					total += shoppingCartProducts[i]->price * shoppingCartCounts[i];
+					shoppingCartProducts[i]->count -= shoppingCartCounts[i];
+				}
+
+				std::cout << "Purchase successful! Total cost: " << total << std::endl;
+
+				delete[] shoppingCartProducts;
+				delete[] shoppingCartCounts;
+			}
+			break;
+
+		case 'a':
+			if (loggedInUser != nullptr) {
+				if (!loggedInUser->isAdmin) {
+					std::cout << "No permissions!" << std::endl;
+					return;
+				}
+
+				User temp;
+
+				readUsername(temp.name, sizeof(temp.name) / sizeof(*temp.name));
+
+				User* registeredUser = users.find(temp.name);
+
+				if (registeredUser == nullptr) {
+					std::cout << "User '" << temp.name << "' does not exist!" << std::endl;
+					return;
+				}
+
+				registeredUser->isAdmin = !registeredUser->isAdmin;
+				if (registeredUser->isAdmin) {
+					std::cout << "Made user '" << registeredUser->name << "' into an administrator." << std::endl;
+				}
+				else {
+					std::cout << "Made administrator '" << registeredUser->name << "' into a user." << std::endl;
+				}
+			}
+			break;
+
+		case 's':
+			if (loggedInUser != nullptr) {
+				if (!loggedInUser->isAdmin) {
+					std::cout << "No permissions!" << std::endl;
+					return;
+				}
+
+				Product temp;
+
+				readName(temp.name, sizeof(temp.name) / sizeof(*temp.name));
+
+				std::cout << "Quantity: ";
+				std::cin >> temp.count;
+
+				std::cout << "Price: ";
+				std::cin >> temp.price;
+				std::cin.ignore();
+
+				Product* storedProduct = products.find(temp.name);
+
+				if (storedProduct == nullptr) {
+					products.add(temp);
+				}
+				else {
+					storedProduct->count += temp.count;
+					storedProduct->price = temp.price;
+				}
+			}
+			break;
+
+		default:
+			std::cout << "Invalid command '" << command << "'!" << std::endl;
+	}
+}
+
+Shop newShop() {
+	Shop s;
+	s.users = newUserArray(64);
+	s.products = newProductArray(64);
+	s.loggedInUser = nullptr;
+	return s;
+}
+
+void deleteShop(Shop& shop) {
+	deleteUserArray(shop.users);
+	deleteProductArray(shop.products);
+	shop.loggedInUser = nullptr;
+}
diff --git a/Week03/Exercise01/Shop.h b/Week03/Exercise01/Shop.h
new file mode 100644
index 0000000..af008bb
--- /dev/null
+++ b/Week03/Exercise01/Shop.h
@@ -0,0 +1,18 @@
+#ifndef _SHOP
+#define _SHOP
+
+#include "User.h"
+#include "Product.h"
+
+struct Shop {
+	UserArray users;
+	ProductArray products;
+	User* loggedInUser;
+
+	void runCommand(char command);
+};
+
+Shop newShop();
+void deleteShop(Shop& shop);
+
+#endif
diff --git a/Week03/Exercise01/User.cpp b/Week03/Exercise01/User.cpp
new file mode 100644
index 0000000..0dca648
--- /dev/null
+++ b/Week03/Exercise01/User.cpp
@@ -0,0 +1,33 @@
+#include <iostream>
+#include <cstring>
+#include "User.h"
+
+void UserArray::add(const User& user) {
+	if (count >= allocated) {
+		std::cout << "No more users are allowed!" << std::endl;
+		return;
+	}
+
+	users[count++] = user;
+}
+
+User* UserArray::find(char* username) {
+	for (unsigned i = 0; i < count; ++i)
+		if (strcmp(username, users[i].name) == 0)
+			return &users[i];
+	return nullptr;
+}
+
+UserArray newUserArray(unsigned allocatedSize) {
+	UserArray ua;
+	ua.users = new User[allocatedSize];
+	ua.count = 0;
+	ua.allocated = allocatedSize;
+	return ua;
+}
+
+void deleteUserArray(UserArray& ua) {
+	delete[] ua.users;
+	ua.users = nullptr;
+	ua.count = ua.allocated = 0;
+}
diff --git a/Week03/Exercise01/User.h b/Week03/Exercise01/User.h
new file mode 100644
index 0000000..4802516
--- /dev/null
+++ b/Week03/Exercise01/User.h
@@ -0,0 +1,22 @@
+#ifndef _USER
+#define _USER
+
+struct User {
+	char name[256];
+	char password[256];
+	bool isAdmin;
+};
+
+struct UserArray {
+	User* users;
+	unsigned count;
+	unsigned allocated;
+
+	void add(const User& user);
+	User* find(char* username);
+};
+
+UserArray newUserArray(unsigned allocatedSize);
+void deleteUserArray(UserArray& ua);
+
+#endif
diff --git a/Week03/Exercise01/main.cpp b/Week03/Exercise01/main.cpp
new file mode 100644
index 0000000..a018dd5
--- /dev/null
+++ b/Week03/Exercise01/main.cpp
@@ -0,0 +1,25 @@
+#include <iostream>
+#include <cstring>
+#include "Shop.h"
+
+int main() {
+	Shop shop = newShop();
+
+	User admin;
+	strcpy(admin.name, "admin");
+	strcpy(admin.password, "admin");
+	admin.isAdmin = true;
+
+	shop.users.add(admin);
+
+	char command;
+	while (true) {
+		std::cin >> command;
+		std::cin.ignore();
+		shop.runCommand(command);
+	}
+
+	deleteShop(shop);
+
+	return 0;
+}