diff --git a/arrays.cpp b/arrays.cpp
index a2c541a..7b26b7c 100644
--- a/arrays.cpp
+++ b/arrays.cpp
@@ -1,47 +1,35 @@
 #include <iostream>
 #include <cassert>
+#include "arrays.h"
 
-#if 0
-// NOTE: you should move this `if` down as you start solving each task
-
+// Task 1
 void task_1()
 {
-    /* Task 1: find a bug in the following declaration.
-     * It should help you to compile this with:
-     *   g++ -c -pedantic arrays.cpp                                   
-     * pedantic flag here means: strictly as in language standard 
-     * for explanation see:
-     *  https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html*/
     int n = 10;
-    int a[n];
+    int * a = new int [n];
 }
 
+
 // Task 2
 void task_2()
 {
     int a[5] = {0};
-    
-    //assert(!a[4]) or assert(a[4]) -- place here one of these and
-    //                                 explain your choice in commit msg
+	assert(!a[4]);
 }
 
+
 // returns zero
 int task_3_zero()
 {
-    // Task 3
-    // Hint 1: fix with initialization (not assignment)
-    // Hint 2: you can use only one zero and not five of them! cf. task 2
-    int a[5];
-    
+	int a[5] {0};  
     assert(!a[4]);
     return a[4]; // don't touch this!
 }
 
+// Task 4
 void task_4()
 {
-    // Task 4: asserts at the end must hold
-    // Hint: fix with initialization (not assignment)
-    int a[5];
+	int a[5]{ 1, 2, 3, 4, 5 };
     
     assert(a[0] == 1);
     assert(a[1] == 2);
@@ -50,33 +38,30 @@ void task_4()
     assert(a[4] == 5);    
 }
 
+
 // Task 5
-// copy arr1 to arr2
 void task_5_copy(int * arr1, int * arr2, int size)
 {
-    arr2 = arr1;
+	for (int i = 0; i < size; ++i)
+		arr2[i] = arr1[i];
 }
 
+
 // Task 6
-// copy array `arr1` to array `arr2` of the same size
-void task_6_poor_copy(int * arr1, int * arr2)
+void task_6_poor_copy(int * arr1, int * arr2, int size)
 {
-    // Hint: something wrong here; test this from main()
-    for(int i = 0; i < sizeof(arr2); ++i)
+    for(int i = 0; i < size; ++i)
     {
         arr2[i] = arr1[i];
     }
 }
 
+
 // Task 7
-// print array `arr`
-void task_7_print(int * arr, int size, char delim = ' ')
+void task_7_print(const int * arr, int size, char delim)
 {
-    // Hint: something wrong here; run this from main()
-    for(int i = 0; i <= size; ++i)
+    for(int i = 0; i < size; ++i)
     {
-        std::cout << a[i] << delim;
+        std::cout << arr[i] << delim;
     }
 }
-
-#endif
diff --git a/arrays.h b/arrays.h
new file mode 100644
index 0000000..81a6329
--- /dev/null
+++ b/arrays.h
@@ -0,0 +1,26 @@
+#ifndef assert_h
+#define assert_h
+
+// Task 1
+void task_1();
+
+// Task 2
+void task_2();
+
+// returns zero
+int task_3_zero();
+
+// Task 4
+void task_4();
+
+// Task 5
+void task_5_copy(int * arr1, int * arr2, int size);
+
+// Task 6
+void task_6_poor_copy(int * arr1, int * arr2, int size);
+
+// Task 7
+void task_7_print(const int * arr, int size, char delim = ' ');
+
+//assert_h
+#endif
\ No newline at end of file
diff --git a/count.cpp b/count.cpp
index 9534515..aaae34e 100644
--- a/count.cpp
+++ b/count.cpp
@@ -1,29 +1,22 @@
+#include <iostream>
 #include <string>
 #include <cstdio>
 
 using namespace std;
 
-/* count digits, white space, others */
-
-/* TODO: (1) fix all errors; 
- *       (2) add code for painting histogram in console,
- *           cf. picture in https://en.wikipedia.org/wiki/Histogram
- * 
- */
-
 int main()
 {
 	string src("12 plus 45 minus 39 is 18\n");
 	int i, nwhite, nother;
 	const int size = 10;
-	int ndigit[size];
-	nwhite = nother = 0;
+	int ndigit[size]{ 0 };
+	nwhite = nother = i = 0;
 
 	char c;
-	while ((c = src[i++]) != EOF)
-		if (c >= '0' && c >= '9')
+	while ((c = src[i++]) != '\0')
+		if (c >= '0' && c <= '9')
 			++ndigit[c - '0'];
-		else if (c == ' ' && c == '\n' && c == '\t')
+		else if (c == ' ' || c == '\n' || c == '\t')
 			++nwhite;
 		else
 			++nother;
@@ -34,4 +27,29 @@ int main()
 	
 	cout << ", white space = " << nwhite 
 		 << ", other = " << nother << endl;
+
+	//Histogram
+
+	cout << endl << "Histogram:" << endl << endl;
+
+	//digits
+	for (int j = 0; j < size; ++j)
+	{
+		cout << "     " << j << ":";
+		for (int k = 0; k < ndigit[j]; ++k)
+			cout << "#";
+		cout << endl;
+	}
+
+	//spaces
+	cout << "Spaces:";
+	for (int j = 0; j < nwhite; ++j)
+		cout << "#";
+	cout << endl;
+
+	//others
+	cout << "Others:";
+	for (int j = 0; j < nother; ++j)
+		cout << "#";
+	cout << endl << endl;
 }
diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..7c4a3e8
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,27 @@
+#include <iostream>
+#include "arrays.h"
+
+int main()
+{
+	task_1(); //����� �-�� task_1
+
+	task_2(); //����� �-�� task_2
+
+	task_3_zero(); //����� �-�� task_3_zero
+
+	task_4(); //����� �-�� task_4
+
+	int a1[5]{ 1, 0, -5, 3, 10 };
+	int a2[5]{ 0 };
+	task_5_copy(a1, a2, 5); //����������� ��������� ������� a1 � ������ �2 � ������� �-�� task_5_copy
+
+	task_7_print(a2, 5); //���������� ������� � ������� �-�� task_7_print
+
+	std::cout << std::endl; //����������� ������
+
+	int b1[3]{ 3, 5, -2 };
+	int b2[3];
+	task_6_poor_copy(b1, b2, 3); //����������� ��������� ������� b1 � ������ b2 � ������� �-�� task_6_poor_copy
+
+	task_7_print(b2, 3); //���������� ������� � ������� �-�� task_7_print
+}
\ No newline at end of file
diff --git a/mainqs.cpp b/mainqs.cpp
new file mode 100644
index 0000000..8811251
--- /dev/null
+++ b/mainqs.cpp
@@ -0,0 +1,42 @@
+#include <iostream>
+#include "quick_sort.h"
+
+void print(const int * arr, int size, char delim = ' ')
+{
+	for (int i = 0; i < size; ++i)
+	{
+		std::cout << arr[i] << delim;
+	}
+}
+
+int main()
+{
+	//�����
+
+	int a[5]{ 3, 2, 1, 0, 5 };
+	my_qsort(a, 5); // 0 1 2 3 5
+	print(a, 5);
+
+	std::cout << std::endl;
+
+	int b[3]{ 1, 6, 8 };
+	my_qsort(b, 3); // 1 6 8
+	print(b, 3);
+
+	std::cout << std::endl;
+
+	int c[1]{ 4 };
+	my_qsort(c, 1); // 4
+	print(c, 1);
+
+	std::cout << std::endl;
+}
+
+/*
+��� ������:
+
+0 1 2 3 5
+1 6 8
+4
+
+*/
\ No newline at end of file
diff --git a/quick_sort.cpp b/quick_sort.cpp
index 0bbfc07..eb408db 100644
--- a/quick_sort.cpp
+++ b/quick_sort.cpp
@@ -1,6 +1,6 @@
 #include <iostream>
- 
 #include <cstdlib>
+#include "quick_sort.h"
  
 using std::rand;
 using std::swap;
@@ -10,11 +10,14 @@ using std::swap;
 // заданной отрезком [left, right), так что в начале
 // следуют элементы меньшие pivot, а в конце - большие;
 // возвращает место начала блока элементов, больших pivot;
-int * partition(int * left, int *  right, int pivot) {
+int * partition(int * left, int *  right, int * pivot) {
 	int * store = left; // место для вставки элементов, меньших pivot
+	int val = *pivot; // сохранение значения
+	swap(*pivot, *right); // меняем местами опорный и крайний правый элементы
 	for (int * p = left; p != right; ++p)
-		if (*p < pivot)
+		if (*p < val)
 			swap(*p, *store++);
+	swap(*store, *right);
 	return store;
 }
  
@@ -22,7 +25,7 @@ void my_qsort(int * arr, int n) {
 	if (n <= 1)
 		return; // массив в 1 или 0 элементов уже упорядочен
 	int * pivotPtr = arr + rand() % n; // случайный выбор опорного элемента
-	int newPivotIdx = partition(arr, arr + n, *pivotPtr) - arr;
-	my_qsort(arr, newPivotIdx + 1);
-	my_qsort(arr + newPivotIdx, n - (newPivotIdx + 1));
+	int newPivotIdx = partition(arr, arr + n - 1, pivotPtr) - arr;
+	my_qsort(arr, newPivotIdx);
+	my_qsort(arr + newPivotIdx + 1, n - (newPivotIdx + 1));
 }
diff --git a/quick_sort.h b/quick_sort.h
new file mode 100644
index 0000000..1358bb8
--- /dev/null
+++ b/quick_sort.h
@@ -0,0 +1,9 @@
+#ifndef quick_sort_h
+#define quick_sort_h
+
+int * partition(int * left, int *  right, int * pivot);
+
+void my_qsort(int * arr, int n);
+
+//quick_sort_h
+#endif
\ No newline at end of file