diff --git a/animals/animal.cpp b/animals/animal.cpp
index 6745215..28c60ff 100644
--- a/animals/animal.cpp
+++ b/animals/animal.cpp
@@ -3,5 +3,19 @@
 using namespace std;
 
 int main() {
+    Elephant eleph(150, 3000., 22);
+    eleph.setWeight(3004.);
+    eleph.setTrunkLength(145);
+    cout << eleph.getTrunkLength() << " " << eleph.getPregnancyDuration() << " " << eleph.getWeight() << "\n";
+
+    Cat cat(14, 7, 1);
+    cout << cat.getVibrissaLength() << " " << cat.getWeight() << " " << cat.getPregnancyDuration() << "\n";
+
+    Penguin penguin(1, 40);
+    cout << penguin.getHeight() << " " << penguin.getWeight() << " " << penguin.getCanFly() << "\n";
+
+    Colibri colibri("blue", 0.02);
+    cout << colibri.getColor() << " " << colibri.getWeight() << " " << colibri.getCanFly() << "\n";
+
 	return 0;
 }
\ No newline at end of file
diff --git a/animals/animal.h b/animals/animal.h
index 83a1944..c251a1c 100644
--- a/animals/animal.h
+++ b/animals/animal.h
@@ -1,18 +1,102 @@
 #pragma once
 
 #include <iostream>
+using namespace std;
 
 class Animal {
+private:
+	float weight;
 public:
-	float weight;				// kg
+    Animal(float w = 0.) {
+        weight = w;
+    }
+    float getWeight() const { return weight; }
+    void setWeight(float w) { weight = w; }
+    virtual void about() {
+        cout << "Weight = " << weight << "\n";
+    }
 };
 
 class Mammal : public Animal {
+private:
+	int pregnancyDuration;
 public:
-	float pregnancyDuration;	// days
+    Mammal(float w = 0., int p = 0) : Animal(w) {
+        pregnancyDuration = p;
+    }
+    float getPregnancyDuration() const { return pregnancyDuration; }
+    void setPregnancyDuration(int p) { pregnancyDuration = p; }
+    virtual void about() {
+        cout << "PregnancyDuration = " << pregnancyDuration << "\n";
+    }
 };
 
 class Cat : public Mammal {
+private:
+	int vibrissaLength;
 public:
-	float vibrissaLength;		// meters
+    Cat(int v = 0, float w = 0., int p = 0) : Mammal(w, p) {
+        vibrissaLength = v;
+    }
+    float getVibrissaLength() const { return vibrissaLength; }
+    void setVibrissaLength(float v) { vibrissaLength = v; }
+    virtual void about() {
+        cout << "VibrissaLength = " << vibrissaLength << "\n";
+    }
+};
+
+class Elephant : public Mammal {
+private:
+    int trunkLength;
+public:
+    Elephant(int t = 0, float w = 0., int p = 0) : Mammal(w, p) {
+        trunkLength = t;
+    }
+    float getTrunkLength() const { return trunkLength; }
+    void setTrunkLength(float t) { trunkLength = t; }
+    virtual void about() {
+        cout << "TrunkLength = " << trunkLength << "\n";
+    }
+};
+
+class Birds : public Animal {
+private:
+    bool canFly;
+public:
+    Birds(bool b = false, float w = 0.) : Animal(w) {
+        canFly = b;
+    }
+    bool getCanFly() const { return canFly; }
+    void setCanFly(bool b) { canFly = b; }
+    virtual void about() {
+        cout << "CanFly = " << canFly << "\n";
+    }
+};
+
+class Penguin : public Birds {
+private:
+    int height;
+public:
+    Penguin(int h = 0, float w = 0.) : Birds(false, w) {
+        height = h;
+    }
+    bool getHeight() const { return height; }
+    void setHeight(int h) { height = h; }
+    virtual void about() {
+        cout << "Height = " << height << "\n";
+    }
+};
+
+class Colibri : public Birds {
+private:
+    string color;
+public:
+    Colibri(string c = "green", float w = 0.) : Birds(true, w) {
+        color = c;
+    }
+    string getColor() const { return color; }
+    void setColor(string c) { color = c; }
+    virtual void about() {
+        cout << "Color = " << color << "\n";
+    }
 };
diff --git a/memhacks/memhacks.cpp b/memhacks/memhacks.cpp
index 514c868..2d3e29d 100644
--- a/memhacks/memhacks.cpp
+++ b/memhacks/memhacks.cpp
@@ -4,54 +4,57 @@
 using namespace std;
 
 B::B() : b_s("It's b!") {
-	for (auto i = 0; i < sizeof(data) / sizeof(data[0]); i++)
-		data[i] = i * 2;
+    for (auto i = 0; i < sizeof(data) / sizeof(data[0]); i++)
+        data[i] = i * 2;
 }
 
-/// <summary>
 /// Выводит на экран адреса и размеры объекта типа <see cref="B"/> и его содержимого.
 /// Можно модифицировать для собственных отладочных целей.
-/// </summary>
-/// <param name="b">Изучаемый объект</param>
-void printInternals(const B& b) {
-	const A* a = &b, * a2 = a + 1;
-	cout << "Address of b is 0x" << &b << ", address of b.a_s is 0x" << &b.a_s << ", address of b.b_s is 0x" << &b.b_s << endl;
-	cout << "Size of A is " << sizeof(A) << ", size of B is " << sizeof(B) << endl;
-	cout << "B string is '" << b.getBString() << "'" << endl;
-	//cout << "B data: "; b.printData(cout); cout << endl;
+void printInternals(const B &b) {
+    const A *a = &b, *a2 = a + 1;
+    cout << "Address of b is 0x" << &b << ", address of b.a_s is 0x" << &b.a_s << ", address of b.b_s is 0x" << &b.b_s
+         << endl;
+    cout << "Size of A is " << sizeof(A) << ", size of B is " << sizeof(B) << endl;
+    cout << "B string is '" << b.getBString() << "'" << endl;
+    //cout << "B data: "; b.printData(cout); cout << endl;
 }
 
-/// <summary>
 /// Извлекает значение <see cref="B::b_s"/> из текущего объекта.
-/// Подразумевается, что текущий объект на самом деле представлено классом <see cref="B"/>.
-/// </summary>
-/// <returns>Значение B::b_s</returns>
 std::string A::getBString() const {
-	// TODO
+    return *((const string *) (this + 1));
 }
 
-/// <summary>
 /// Извлекает значения <see cref="A::a_s"/>, <see cref="B::b_s"/> и <see cref="B::data"/>
 /// из текущего объекта и выводит их в текстовом виде в указанный выходной поток
 /// с помощью адресной арифметики.
-/// Подразумевается, что текущий объект на самом деле представлено классом <see cref="B"/>.
-/// </summary>
-void A::printData(std::ostream& os) {
-	// TODO
+void A::printData(std::ostream &os) {
+    os << "A::a_s: " << a_s << "\n";
+    os << "B::b_s: " << A::getBString() << "\n";
+    os << "B::data: ";
+
+    const float *bData = ((const float *) (((const std::string *) (this + 1)) + 1));
+    for (int i = 0; i < 7; ++i) {
+        os << bData[i] << " ";
+    }
+    os << "\n";
 }
 
-/// <summary>
 /// Извлекает значения <see cref="A::a_s"/>, <see cref="B::b_s"/> и <see cref="B::data"/>
 /// из текущего объекта и выводит их в текстовом виде в указанный выходной поток
 /// с помощью виртуальных функций, предусмотренных в классе <see cref="A"/>.
-/// </summary>
-void A::printData2(std::ostream& os) {
-	// TODO
-}
+void A::printData2(std::ostream &os) {
+    os << "A::a_s: " << *A::getString() << "\n";
+    os << "B::b_s: " << *getString() << "\n";
 
-int main()
-{
-	B b;
-	printInternals(b);
-	return 0;
+    const float *bData = getData();
+    for (int i = 0; i < 7; ++i) {
+        os << bData[i] << " ";
+    }
+    os << "\n";
 }
+
+int main() {
+    B b;
+    printInternals(b);
+    return 0;
+}
\ No newline at end of file
diff --git a/memhacks/memhacks.h b/memhacks/memhacks.h
index 51076b5..7c583ce 100644
--- a/memhacks/memhacks.h
+++ b/memhacks/memhacks.h
@@ -6,25 +6,36 @@
 class B;	// чтобы можно было объявить printInternals() как friend в классе A
 
 class A {
-	std::string a_s;
-	int foo;
+    std::string a_s;
+    int foo;
 
-	friend void printInternals(const B&);
+    friend void printInternals(const B&);
 
 public:
-	std::string getBString() const;
-	void printData(std::ostream& os);
-	void printData2(std::ostream& os);
+    std::string getBString() const;
+    void printData(std::ostream& os);
+    void printData2(std::ostream& os);
+
+    virtual const std::string* getString() const {
+        return &a_s;
+    };
+    virtual const float* getData() const {}
 };
 
 class B : public A {
-	std::string b_s;
-	float data[7];
+    std::string b_s;
+    float data[7];
 
-	friend void printInternals(const B&);
+    friend void printInternals(const B&);
 
 public:
-	B();
+    B();
+    virtual const std::string* getString() const {
+        return &b_s;
+    }
+    virtual const float* getData() const {
+        return data;
+    }
 };
 
-void printInternals(const B& b);
+void printInternals(const B& b);
\ No newline at end of file
diff --git a/memhacks/newhacks.cpp b/memhacks/newhacks.cpp
index ba359c6..b3ea9b2 100644
--- a/memhacks/newhacks.cpp
+++ b/memhacks/newhacks.cpp
@@ -1,9 +1,23 @@
 #include <iostream>
-#include "memhacks.h"
+#include "newhacks.h"
 
 using namespace std;
 
-int main()
-{
-	return 0;
+void solve() {
+    //Создание всех трех элементов на стеке
+    Foo f(1, 'a'); Bar b(13); Buz z(123);
+
+    //Создание всех трех элементов в динамической памяти
+    Foo *f1 = new Foo; Bar *b1 = new Bar; Buz *z1 = new Buz;
+    delete f1; delete b1; delete z1;
+
+    //Для того чтобы запретить создание элемента типа Buz
+    //достаточно operator new/delete записать в private:
+}
+
+int main() {
+    solve();
+
+
+    return 0;
 }
diff --git a/memhacks/newhacks.h b/memhacks/newhacks.h
index 079a383..fc65426 100644
--- a/memhacks/newhacks.h
+++ b/memhacks/newhacks.h
@@ -1,2 +1,82 @@
 #pragma once
 
+#include <sys/types.h>
+#include <cstdlib>
+#include <iostream>
+
+class Foo {
+    int id;
+    char a{};
+public:
+    Foo(int a = 0, char b = ' ') {
+        std::cout << "Default constructor Foo:\n";
+        id = a;
+        a = b;
+    };
+
+    ~Foo() {
+        std::cout << "Default destructor Foo:\n";
+    };
+
+    int get_id() const { return id; }
+
+    char get_char() const { return a; }
+
+    static void *operator new(size_t size) {
+        std::cout << "Operator new for Foo:\n";
+        auto m = malloc(size);
+        return m;
+    };
+
+    static void operator delete(void *m) {
+        std::cout << "Operator delete for Foo:\n";
+        free(m);
+    };
+};
+
+class Bar : public Foo {
+    int id1;
+public:
+    Bar(int a = 0) {
+        std::cout << "Default constructor for Bar:\n";
+        id1 = a;
+    };
+
+    ~Bar() {
+        std::cout << "Default destructor for Bar:\n";
+    };
+
+    static void *operator new(size_t size) {
+        std::cout << "Operator new for Bar:\n";
+        auto m = malloc(size);
+        return m;
+    };
+
+    static void operator delete(void *m) {
+        std::cout << "Operator delete for Bar:\n";
+        free(m);
+    };
+};
+
+class Buz : public Foo {
+    int id2;
+public:
+    Buz(int a = 0) {
+        std::cout << "Default constructor for Buz:\n";
+        id2 = a;
+    };
+
+    ~Buz() {
+        std::cout << "Default destructor for Buz:\n";
+    };
+    static void *operator new(size_t size) {
+        std::cout << "Operator new for Buz:\n";
+        auto m = malloc(size);
+        return m;
+    };
+
+    static void operator delete(void *m) {
+        std::cout << "Operator delete for Buz:\n";
+        free(m);
+    };
+};
\ No newline at end of file
diff --git a/vectors/array.cpp b/vectors/array.cpp
index 555ccad..2ee32f8 100644
--- a/vectors/array.cpp
+++ b/vectors/array.cpp
@@ -1,28 +1,127 @@
-#include "array.h"
+#include <iostream>
 
 using namespace std;
 
-// Написать шаблонные функции:
-//   1. operator + (реализация внутри класса)
-//   2. operator * (вектор на скаляр и скаляр на вектор; реализация вне класса)
-//   3. Нахождение среднего для двух векторов (реализация вне класса)
+class Vector3d {
+    float data[3];
+public:
+    Vector3d() { data[2] = data[1] = data[0] = 0; }
 
-ostream& operator <<(ostream& os, const Vector3d& v) {
-    return os << "{ " << v[0] << ", " << v[1] << ", " << v[2] << " }";
+    Vector3d(float value) { data[2] = data[1] = data[0] = value; }
+
+    Vector3d(float a1, float a2, float a3) {
+        data[0] = a1;
+        data[1] = a2;
+        data[2] = a3;
+    }
+
+    float operator[](int index) const {
+        cerr << "const" << index << endl;
+        return data[index];
+    }
+
+    float &operator[](int index) {
+        cerr << "non-const" << index << endl;
+        return data[index];
+    }
+
+    Vector3d operator+(const Vector3d &v2) {
+        Vector3d v3;
+        v3[0] = data[0] + v2[0];
+        v3[1] = data[1] + v2[1];
+        v3[2] = data[2] + v2[1];
+        return v3;
+    }
+
+    Vector3d operator*(const float value) {
+        Vector3d v3;
+        v3[0] = data[0] * value;
+        v3[1] = data[1] * value;
+        v3[2] = data[2] * value;
+        return v3;
+    }
+
+    Vector3d operator-(const Vector3d &v2) {
+        Vector3d v3;
+        v3[0] = data[0] - v2[0];
+        v3[1] = data[1] - v2[1];
+        v3[2] = data[2] - v2[2];
+        return v3;
+    }
+
+    Vector3d operator/(const float value) {
+        if (value == 0) {
+            cout << "Value is not correct\n";
+            return 0;
+        }
+        Vector3d v3;
+        v3[0] = data[0] / value;
+        v3[1] = data[1] / value;
+        v3[2] = data[2] / value;
+        return v3;
+    }
+
+    Vector3d operator-() { return Vector3d(-data[0], -data[1], -data[2]); }
+
+    Vector3d operator!() {
+        if (data[0] == data[1] == data[2] == 0) {
+            return Vector3d(1, 1, 1);
+        }
+        return Vector3d(0, 0, 0);
+    }
+};
+
+ostream &operator<<(ostream &os, const Vector3d &v) {
+    return os << "{  " << v[0] << ", " << v[1] << ", " << v[2] << " }";
 }
 
-template<size_t Dimensions>
-ostream& operator <<(ostream& os, const Vector<Dimensions>& v) {
-    os << "{ " << v[0];
-    for (size_t i = 1; i < Dimensions; i++)
-        os << ", " << v[i];
-    return os << " }";
+bool test_vector3d() {
+    Vector3d v1(4, 4, 4);
+    Vector3d v2(1, 1, 1);
+    Vector3d v3;
+    Vector3d v4(0, 0, 0);
+    v3 = v1 + v2;
+    if ((v3[0] != 5) || (v3[1] != 5) || (v3[2] != 5)) {
+        cerr << "The addition operation does not work correctly with data - v1(4,4,4), v2(1,1,1)";
+        return false;
+    }
+    v3 = v1 - v2;
+    if ((v3[0] != 3) || (v3[1] != 3) || (v3[2] != 3)) {
+        cerr << "The subtract operation does not work correctly with data - v1(4,4,4), v2(1,1,1)";
+        return false;
+    }
+    v3 = v1 * 3;
+    if ((v3[0] != 12) || (v3[1] != 12) || (v3[2] != 12)) {
+        cerr << "The operation of multiplying by a number does not work correctly with data - v1(4,4,4), 3";
+        return false;
+    }
+    v3 = v1 / 4;
+    if ((v3[0] != 1) || (v3[1] != 1) || (v3[2] != 1)) {
+        cerr << "The operation of division by a number does not work correctly with data - v1(5,5,5), 4";
+        return false;
+    }
+    v3 = -v1;
+    if ((v3[0] != -4) || (v3[1] != -4) || (v3[2] != -4)) {
+        cerr << "Unary minus does not work correctly with data - v1(5,5,5)";
+        return false;
+    }
+    v3 = !v1;
+    if ((v3[0] != 0) || (v3[1] != 0) || (v3[2] != 0)) {
+        cerr << "Unary ! works incorrectly with data - v4(0,0,0)";
+        return false;
+    }
+    v3 = !v4;
+    if ((v3[0] != 1) || (v3[1] != 1) || (v3[2] != 1)) {
+        cerr << "Unary ! works incorrectly with data - v1(1,1,1)";
+        return false;
+    }
+    return true;
 }
 
 int main() {
-    Vector<12> v1;
-    v1[1] = v1[2] = 54;
-    Vector<12> v2 = v1;
-    cout << v2 << endl;
-	return 0;
-}
+    if (test_vector3d()) {
+        return 0;
+    } else {
+        return 1;
+    }
+}
\ No newline at end of file