diff --git a/sem2/ReznikovIA/hw4/main.cpp b/sem2/ReznikovIA/hw4/main.cpp
new file mode 100644
index 00000000..f68fba45
--- /dev/null
+++ b/sem2/ReznikovIA/hw4/main.cpp
@@ -0,0 +1,108 @@
+#include <algorithm>
+#include <fstream>
+#include <iostream>
+#include <numeric>
+#include <random>
+#include <string>
+#include <vector>
+
+std::vector<int> generateVector();
+void workWithArray(std::vector<int>& numbers);
+void writeToFile(const std::vector<int>& data,
+                 const std::string& outputFileName);
+void writeToFile(const std::string& data, const std::string& outputFileName);
+void writeToFile(const double& data, const std::string& outputFileName);
+
+void clearFile(const std::string& fileName);
+
+int main() {
+  std::vector<int> numbers = generateVector();
+  workWithArray(numbers);
+  return 0;
+}
+
+void workWithArray(std::vector<int>& numbers) {
+  std::string fileName = "output.txt";
+  clearFile(fileName);
+
+  auto maxElemIt = std::max_element(numbers.cbegin(), numbers.cend());
+  writeToFile("max: " + std::to_string((*maxElemIt)), fileName);
+  auto minElemIt = std::min_element(numbers.cbegin(), numbers.cend());
+  writeToFile("min: " + std::to_string((*minElemIt)), fileName);
+
+  std::sort(numbers.begin(), numbers.end());
+  writeToFile("sorted", fileName);
+  writeToFile(numbers, fileName);
+
+  int positiveCount =
+      std::count_if(numbers.cbegin(), numbers.cend(),
+                    [](int number) -> bool { return number > 0; });
+  writeToFile("+: " + std::to_string(positiveCount), fileName);
+  int negativeCount =
+      std::count_if(numbers.cbegin(), numbers.cend(),
+                    [](int number) -> bool { return number < 0; });
+  writeToFile("-: " + std::to_string(negativeCount), fileName);
+
+  int zeroCount = std::count_if(numbers.cbegin(), numbers.cend(),
+                                [](int number) -> bool { return number == 0; });
+  writeToFile("0: " + std::to_string(zeroCount), fileName);
+
+  double mean = std::accumulate(numbers.cbegin(), numbers.cend(), 0) /
+                static_cast<double>(numbers.size());
+  writeToFile("arithmetic mean: " + std::to_string(mean), fileName);
+
+  auto newEnd = std::remove_if(numbers.begin(), numbers.end(),
+                               [](int num) { return num % 2 == 0; });
+  numbers.erase(newEnd, numbers.end());
+  writeToFile("only odd", fileName);
+  writeToFile(numbers, fileName);
+
+  std::sort(numbers.begin(), numbers.end());
+  std::vector<int> uniqueNumbers;
+  std::unique_copy(numbers.begin(), numbers.end(),
+                   std::back_inserter(uniqueNumbers));
+  writeToFile("sorted unique", fileName);
+  writeToFile(uniqueNumbers, fileName);
+}
+
+std::vector<int> generateVector() {
+  std::vector<int> nums(20);
+  std::random_device rd;
+  std::mt19937 gen(rd());
+  std::uniform_int_distribution<int> dist(-50, 100);
+
+  std::generate(nums.begin(), nums.end(),
+                [&dist, &gen]() { return dist(gen); });
+  return nums;
+}
+
+void clearFile(const std::string& fileName) {
+  std::ofstream out(fileName);
+  if (out.is_open()) {
+  }
+  out.close();
+}
+
+void writeToFile(const std::string& data, const std::string& fileName) {
+  std::ofstream out(fileName, std::ios::app);
+  if (out.is_open()) {
+    out << data << std::endl;
+  }
+  out.close();
+}
+
+void writeToFile(const double& data, const std::string& fileName) {
+  std::ofstream out(fileName, std::ios::app);
+  if (out.is_open()) {
+    out << data << std::endl;
+  }
+  out.close();
+}
+
+void writeToFile(const std::vector<int>& data,
+                 const std::string& outputFileName) {
+  std::for_each(data.cbegin(), data.cend(),
+                [&data, &outputFileName](const int num) {
+                  writeToFile(std::to_string(num), outputFileName);
+                });
+}
diff --git a/sem2/ReznikovIA/hw4/output.txt b/sem2/ReznikovIA/hw4/output.txt
new file mode 100644
index 00000000..ce5976eb
--- /dev/null
+++ b/sem2/ReznikovIA/hw4/output.txt
@@ -0,0 +1,53 @@
+max: 85
+min: -49
+sorted
+-49
+-47
+-46
+-38
+-23
+-19
+-15
+1
+18
+22
+29
+32
+37
+56
+57
+58
+63
+70
+77
+85
++: 13
+-: 7
+0: 0
+arithmetic mean: 18.400000
+only odd
+-49
+-47
+-23
+-19
+-15
+1
+29
+37
+57
+63
+77
+85
+sorted unique
+-49
+-47
+-23
+-19
+-15
+1
+29
+37
+57
+63
+77
+85