feat(Week09): Add solutions

3 files changed, 229 insertions, 0 deletions

diff --git a/Week09/Exercise03/String.cpp b/Week09/Exercise03/String.cpp
new file mode 100644
index 0000000..a0b2565
--- /dev/null
+++ b/Week09/Exercise03/String.cpp
@@ -0,0 +1,153 @@
+#include "String.h"
+#include <cstring>
+
+void String::free() {
+	delete[] str;
+}
+
+void String::copyFrom(const String& other) {
+	length = other.length;
+	// Не забравяме за терминиращата нула
+	str = new char[length + 1];
+	strcpy(str, other.str);
+}
+
+String::String() {
+	str = nullptr;
+	length = 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(String&& other) {
+	str = other.str;
+	length = other.length;
+
+	other.str = nullptr;
+	other.length = 0;
+}
+
+String& String::operator=(String&& other) {
+	if (this != &other) {
+		free();
+
+		str = other.str;
+		length = other.length;
+
+		str = nullptr;
+		length = 0;
+	}
+	return *this;
+}
+
+String::String(const char* str) {
+	this->length = strlen(str);
+	this->str = new char[this->length + 1];
+	strcpy(this->str, str);
+}
+
+std::ostream& operator<<(std::ostream& ostr, const String& string) {
+	if (string.str == nullptr)
+		return ostr << "";
+	return ostr << string.str;
+}
+
+String& String::operator+=(const String& other) {
+	char* largerStr = new char[length + other.length + 1];
+	strcpy(largerStr, str);
+	strcat(largerStr, other.str);
+
+	delete[] str;
+	str = largerStr;
+	length += other.length;
+
+	return *this;
+}
+
+char String::operator[](unsigned index) const {
+	return str[index];
+}
+
+String::IndexRange::IndexRange(unsigned index) {
+	start = end = index;
+}
+
+String::IndexRange& String::IndexRange::operator,(const IndexRange& rhs) {
+	if (rhs.start < this->start)
+		this->start = rhs.start;
+	if (this->end < rhs.end)
+		this->end = rhs.end;
+	return *this;
+}
+
+String String::operator[](IndexRange range) const {
+	if (range.end >= length)
+		range.end = length - 1;
+	if (range.start > range.end)
+		return String();
+	if (range.start == 0 && range.end == length - 1)
+		return *this;
+
+	String substr;
+	substr.length = range.end - range.start + 1;
+	substr.str = new char[substr.length + 1];
+
+	strncpy(substr.str, str + range.start, substr.length);
+	substr.str[substr.length] = '\0';
+
+	return substr;
+}
+
+bool operator==(const String& lhs, const String& rhs) {
+	return strcmp(lhs.str, rhs.str) == 0;
+}
+
+bool operator!=(const String& lhs, const String& rhs) {
+	return !(lhs == rhs);
+}
+
+bool operator<(const String& lhs, const String& rhs) {
+	return strcmp(lhs.str, rhs.str) < 0;
+}
+
+bool operator<=(const String& lhs, const String& rhs) {
+	return strcmp(lhs.str, rhs.str) <= 0;
+}
+
+bool operator>(const String& lhs, const String& rhs) {
+	return strcmp(lhs.str, rhs.str) > 0;
+}
+
+bool operator>=(const String& lhs, const String& rhs) {
+	return strcmp(lhs.str, rhs.str) >= 0;
+}
+
+bool operator<<(const String& lhs, const String& rhs) {
+	if (rhs.length > lhs.length)
+		return false;
+	return strcmp(lhs.str + (lhs.length - rhs.length), rhs.str) == 0;
+}
+
+bool operator>>(const String& lhs, const String& rhs) {
+	if (lhs.length > rhs.length)
+		return false;
+	return strncmp(lhs.str, rhs.str, lhs.length) == 0;
+}
+
+String operator+(const String& lhs, const String& rhs) {
+	return String(lhs) += rhs;
+}
diff --git a/Week09/Exercise03/String.h b/Week09/Exercise03/String.h
new file mode 100644
index 0000000..674813c
--- /dev/null
+++ b/Week09/Exercise03/String.h
@@ -0,0 +1,61 @@
+#ifndef _STRING
+#define _STRING
+
+#include <ostream>
+
+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(String&& other);
+	String& operator=(String&& other);
+
+	// Помощни член-функции, за да тестваме String
+	String(const char* str);
+	friend std::ostream& operator<<(std::ostream& ostr, const String& string);
+
+	// Каза ни са кои оператори трябва да бъдат имплементирани,
+	// но както помощни функции, можем да си имплементираме и други
+	// оператори
+	String& operator+=(const String& other);
+
+    char operator[](unsigned index) const;
+
+	const char* te() const {
+		return str;
+	}
+
+	struct IndexRange {
+		unsigned start;
+		unsigned end;
+
+		IndexRange(unsigned index);
+		IndexRange& operator,(const IndexRange& rhs);
+	};
+	String operator[](IndexRange range) const;
+
+	// Алтернативно, може да създадем селектори
+	// GetStr който връща str указателя и GetLength,
+	// и тези функции няма да е нужно да са приятелски
+	friend bool operator==(const String& lhs, const String& rhs);
+	friend bool operator!=(const String& lhs, const String& rhs);
+	friend bool operator<(const String& lhs, const String& rhs);
+	friend bool operator<=(const String& lhs, const String& rhs);
+	friend bool operator>(const String& lhs, const String& rhs);
+	friend bool operator>=(const String& lhs, const String& rhs);
+	friend bool operator<<(const String& lhs, const String& rhs);
+	friend bool operator>>(const String& lhs, const String& rhs);
+};
+
+String operator+(const String& lhs, const String& rhs);
+
+#endif /* _STRING */
diff --git a/Week09/Exercise03/main.cpp b/Week09/Exercise03/main.cpp
new file mode 100644
index 0000000..087b05f
--- /dev/null
+++ b/Week09/Exercise03/main.cpp
@@ -0,0 +1,15 @@
+#include "String.h"
+#include <iostream>
+
+int main() {
+	String a = "Hello";
+	String b = "World";
+
+	String c = a + " " + b;
+
+	std::cout << c << std::endl;
+	std::cout << (c << b) << ' ' << (a >> c) << std::endl;
+	std::cout << c[String::IndexRange(2), 7] << std::endl;
+
+	return 0;
+}