feat(Week04): Add solutions

7 files changed, 311 insertions, 0 deletions

diff --git a/Week04/Exercise01/Train.cpp b/Week04/Exercise01/Train.cpp
new file mode 100644
index 0000000..5ff2db1
--- /dev/null
+++ b/Week04/Exercise01/Train.cpp
@@ -0,0 +1,24 @@
+#include "Train.h"
+#include <iostream>
+
+void Train::ArriveAtStation(unsigned passengersGettingOff, unsigned passengersGettingOn) {
+	if (passengersGettingOff > passengersOnBoard)
+		passengersOnBoard = 0;
+	else
+		passengersOnBoard -= passengersGettingOff;
+
+	passengersOnBoard += passengersGettingOn;
+	earnings += passengersGettingOn * ticketPrice;
+
+	passedStops++;
+	upcomingStops--;
+}
+
+void Train::Print() {
+	std::cout << "Carriages: " << carriages << ' '
+		<< "Seats: " << passengersOnBoard << '/' << seatsAvailable << ' '
+		<< "Stops: " << passedStops << " < " << upcomingStops << ' '
+		<< "Ticket: " << ticketPrice << ' '
+		<< "Earnings: " << earnings
+		<< std::endl;
+}
diff --git a/Week04/Exercise01/Train.h b/Week04/Exercise01/Train.h
new file mode 100644
index 0000000..88322a2
--- /dev/null
+++ b/Week04/Exercise01/Train.h
@@ -0,0 +1,107 @@
+#ifndef _TRAIN
+#define _TRAIN
+
+class Train {
+	unsigned carriages;
+	unsigned seatsAvailable;
+	unsigned passengersOnBoard;
+	unsigned passedStops;
+	unsigned upcomingStops;
+	double ticketPrice;
+	double earnings;
+
+	// Излишно, но е добре да следваме "шаблона"
+	void free() {}
+	void copyFrom(const Train& other) {
+		carriages = other.carriages;
+		seatsAvailable = other.seatsAvailable;
+		passengersOnBoard = other.passengersOnBoard;
+		passedStops = other.passedStops;
+		upcomingStops = other.upcomingStops;
+		ticketPrice = other.ticketPrice;
+		earnings = other.earnings;
+	}
+
+public:
+	// "Шаблон" за голямата четворка
+	Train() {
+		carriages = seatsAvailable = passengersOnBoard = passedStops = upcomingStops = ticketPrice = earnings = 0;
+	}
+	~Train() {
+		free();
+	}
+	Train(const Train& other) {
+		copyFrom(other);
+	}
+	Train& operator=(const Train& other) {
+		if (this != &other) {
+			free();
+			copyFrom(other);
+		}
+		return *this;
+	}
+
+	Train(unsigned carriages, unsigned seatsAvailable, unsigned upcomingStops, double ticketPrice) {
+		this->carriages = carriages;
+		this->seatsAvailable = seatsAvailable;
+		this->passengersOnBoard = 0;
+		this->passedStops = 0.0;
+		this->upcomingStops = upcomingStops;
+		this->ticketPrice = ticketPrice;
+		this->earnings = 0.0;
+	}
+
+	void ArriveAtStation(unsigned passengersGettingOff, unsigned passengersGettingOn);
+	void Print();
+
+	unsigned GetCarriages() {
+		return carriages;
+	}
+	void SetCarriages(unsigned carriages) {
+		this->carriages = carriages;
+	}
+
+	unsigned GetSeatsAvailable() {
+		return seatsAvailable;
+	}
+	void SetSeatsAvailable(unsigned seatsAvailable) {
+		this->seatsAvailable = seatsAvailable;
+	}
+
+	unsigned GetPassengersOnBoard() {
+		return passengersOnBoard;
+	}
+	void SetPassengersOnBoard(unsigned passengersOnBoard) {
+		this->passengersOnBoard = passengersOnBoard;
+	}
+
+	unsigned GetPassedStops() {
+		return passedStops;
+	}
+	void SetPassedStops(unsigned passedStops) {
+		this->passedStops = passedStops;
+	}
+
+	unsigned GetUpcomingStops() {
+		return upcomingStops;
+	}
+	void SetUpcomingStops(unsigned upcomingStops) {
+		this->upcomingStops = upcomingStops;
+	}
+
+	double GetTicketPrice() {
+		return ticketPrice;
+	}
+	void SetTicketPrice(double ticketPrice) {
+		this->ticketPrice = ticketPrice;
+	}
+
+	double GetEarnings() {
+		return earnings;
+	}
+	void SetEarnings(double earnings) {
+		this->earnings = earnings;
+	}
+};
+
+#endif /* _TRAIN */
diff --git a/Week04/Exercise02/IntArray.cpp b/Week04/Exercise02/IntArray.cpp
new file mode 100644
index 0000000..2dc0521
--- /dev/null
+++ b/Week04/Exercise02/IntArray.cpp
@@ -0,0 +1,27 @@
+#include "IntArray.h"
+
+int IntArray::At(unsigned index) {
+	if (index < capacity)
+		return elems[index];
+	return 0;
+}
+
+void IntArray::Resize(unsigned capacity) {
+	int* newElems = new int[capacity];
+
+	unsigned copyCount = this->capacity < capacity ? this->capacity : capacity;
+	for (unsigned i = 0; i < copyCount; ++i)
+		newElems[i] = elems[i];
+
+	delete[] elems;
+	elems = newElems;
+	this->capacity = capacity;
+}
+
+void IntArray::Concat(const IntArray& endElements) {
+	unsigned oldCapacity = capacity;
+	Resize(capacity + endElements.capacity);
+
+	for (unsigned i = oldCapacity; i < capacity; ++i)
+		elems[i] = endElements.elems[i - oldCapacity];
+}
diff --git a/Week04/Exercise02/IntArray.h b/Week04/Exercise02/IntArray.h
new file mode 100644
index 0000000..0ed99c9
--- /dev/null
+++ b/Week04/Exercise02/IntArray.h
@@ -0,0 +1,44 @@
+#ifndef _INTARRAY
+#define _INTARRAY
+
+class IntArray {
+	int* elems;
+	unsigned capacity;
+
+	/* Как трябва да изглежда голяма четворка: */
+
+	void free() {
+		delete[] elems;
+	}
+	void copyFrom(const IntArray& other) {
+		capacity = other.capacity;
+
+		elems = new int[capacity];
+		for (unsigned i = 0; i < capacity; ++i)
+			elems[i] = other.elems[i];
+	}
+public:
+	IntArray() {
+		elems = nullptr;
+		capacity = 0;
+	}
+	~IntArray() {
+		free();
+	}
+	IntArray(const IntArray& other) {
+		copyFrom(other);
+	}
+	IntArray& operator=(const IntArray& other) {
+		if (this != &other) {
+			free();
+			copyFrom(other);
+		}
+		return *this;
+	}
+
+	int At(unsigned index);
+	void Resize(unsigned capacity);
+	void Concat(const IntArray& endElements);
+};
+
+#endif /* _INTARRAY */
diff --git a/Week04/Exercise03/String.cpp b/Week04/Exercise03/String.cpp
new file mode 100644
index 0000000..4fe49f4
--- /dev/null
+++ b/Week04/Exercise03/String.cpp
@@ -0,0 +1,81 @@
+#include "String.h"
+#include "string.h"
+
+void String::free() {
+	delete[] str;
+}
+void String::copyFrom(const String& other) {
+	length = other.length;
+
+	// Не забравяме за терминиращата нула!
+	str = new char[length + 1];
+	for (unsigned i = 0; i <= length; ++i)
+		str[i] = other.str[i];
+}
+
+String::String() {
+	length = 0;
+	str = new char[1];
+	str[0] = '\0';
+}
+
+String::~String() {
+	free();
+}
+
+String::String(const String& other) {
+	copyFrom(other);
+}
+
+String& String::operator=(const String& other) {
+	if (this != &other) {
+		free();
+		copyFrom(other);
+	}
+	return *this;
+}
+
+String::String(const char* str) {
+	length = strlen(str);
+
+	this->str = new char[length + 1];
+	for (unsigned i = 0; i <= length; ++i)
+		this->str[i] = str[i];
+}
+
+unsigned String::GetLength() {
+	return length;
+}
+
+const char* String::GetStr() {
+	return str;
+}
+
+String String::Substring(unsigned startIndex, unsigned endIndex) {
+	if (endIndex >= length)
+		endIndex = length - 1;
+
+	String ret;
+	// Не забравяме за терминиращата нула!
+	ret.length = endIndex - startIndex + 2;
+
+	ret.str = new char[ret.length];
+	for (unsigned i = 0; i <= ret.length; ++i)
+		ret.str[i] = this->str[i + startIndex];
+
+	return ret;
+}
+
+String String::Concat(const String& rightHalf) {
+	String ret;
+	// Не забравяме за терминиращата нула!
+	ret.length = length + rightHalf.length + 1;
+
+	ret.str = new char[ret.length];
+	for (unsigned i = 0; i < length; ++i)
+		ret.str[i] = this->str[i];
+	for (unsigned i = 0; i <= rightHalf.length; ++i)
+		ret.str[i + length] = this->str[i];
+
+	return ret;
+}
diff --git a/Week04/Exercise03/String.h b/Week04/Exercise03/String.h
new file mode 100644
index 0000000..e7d1983
--- /dev/null
+++ b/Week04/Exercise03/String.h
@@ -0,0 +1,25 @@
+#ifndef _STRING
+#define _STRING
+
+class String {
+	char* str;
+	unsigned length;
+
+	void free();
+	void copyFrom(const String& other);
+public:
+	String();
+	~String();
+	String(const String& other);
+	String& operator=(const String& other);
+
+	String(const char* str);
+
+	unsigned GetLength();
+	const char* GetStr();
+
+	String Substring(unsigned startIndex, unsigned endIndex);
+	String Concat(const String& rightHalf);
+};
+
+#endif /* _STRING */
diff --git a/Week04/README.md b/Week04/README.md
new file mode 100644
index 0000000..2627dfb
--- /dev/null
+++ b/Week04/README.md
@@ -0,0 +1,3 @@
+# Задачи
+
+<https://syndamia.com/teaching/oop-2025/week04/>