diff --git a/task_01/src/main.cpp b/task_01/src/main.cpp
index 0e4393ba..e62d14ca 100644
--- a/task_01/src/main.cpp
+++ b/task_01/src/main.cpp
@@ -1,3 +1,17 @@
 #include <iostream>
+#include <utility>
+#include <vector>
 
-int main() { return 0; }
+#include "searching_sum.hpp"
+
+int main() {
+  int n, k;
+  std::cin >> n >> k;
+  std::vector<int> vec(n);
+  for (int i = 0; i < n; i++) {
+    std::cin >> vec[i];
+  }
+  std::pair<int, int> ans = SearchingSum(vec, k);
+  std::cout << ans.first << " " << ans.second << std::endl;
+  return 0;
+}
diff --git a/task_01/src/searching_sum.cpp b/task_01/src/searching_sum.cpp
new file mode 100644
index 00000000..666700c8
--- /dev/null
+++ b/task_01/src/searching_sum.cpp
@@ -0,0 +1,17 @@
+#include "searching_sum.hpp"
+
+#include <utility>
+
+std::pair<int, int> SearchingSum(std::vector<int> vec, int num) {
+  int start = 0;
+  int end = vec.size() - 1;
+  while (start < end) {
+    if (vec[start] + vec[end] > num)
+      --end;
+    else if (vec[start] + vec[end] < num)
+      ++start;
+    else
+      return std::make_pair(start, end);
+  }
+  return std::make_pair(-1, -1);
+}
\ No newline at end of file
diff --git a/task_01/src/searching_sum.hpp b/task_01/src/searching_sum.hpp
new file mode 100644
index 00000000..139727d5
--- /dev/null
+++ b/task_01/src/searching_sum.hpp
@@ -0,0 +1,9 @@
+#ifndef SEARCHING_SUM_HPP
+#define SEARCHING_SUM_HPP
+
+#include <utility>
+#include <vector>
+
+std::pair<int, int> SearchingSum(std::vector<int> vec, int num);
+
+#endif  // define Searching_sum.hpp
\ No newline at end of file
diff --git a/task_01/src/test.cpp b/task_01/src/test.cpp
index ef5a86ae..eb03eaeb 100644
--- a/task_01/src/test.cpp
+++ b/task_01/src/test.cpp
@@ -1,8 +1,48 @@
-
 #include <gtest/gtest.h>
 
-#include "topology_sort.hpp"
+#include <utility>
+#include <vector>
+
+#include "searching_sum.hpp"
 
 TEST(TopologySort, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
+  int sum1 = 6;
+  std::vector<int> vec1{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+  std::pair<int, int> ans1{0, 6};
+  ASSERT_EQ(SearchingSum(vec1, sum1), ans1);
+
+  int sum2 = 6;
+  std::vector<int> vec2{0};
+  std::pair<int, int> ans2{-1, -1};
+  ASSERT_EQ(SearchingSum(vec2, sum2), ans2);
+
+  int sum3 = 4;
+  std::vector<int> vec3{-11, -6, 0, 1, 2, 4, 10, 16};
+  std::pair<int, int> ans3{1, 6};
+  ASSERT_EQ(SearchingSum(vec3, sum3), ans3);
+
+  int sum4 = 0;
+  std::vector<int> vec4{-17, -8, -1, 1, 2, 4, 10};
+  std::pair<int, int> ans4{2, 3};
+  ASSERT_EQ(SearchingSum(vec4, sum4), ans4);
+
+  int sum5 = -9;
+  std::vector<int> vec5{-17, -8, -1, 1, 2, 4, 10};
+  std::pair<int, int> ans5{1, 2};
+  ASSERT_EQ(SearchingSum(vec5, sum5), ans5);
+
+  int sum6 = 17;
+  std::vector<int> vec6{-17, -8, -1, 1, 2, 4, 10};
+  std::pair<int, int> ans6{-1, -1};
+  ASSERT_EQ(SearchingSum(vec6, sum6), ans6);
+
+  int sum7 = -1;
+  std::vector<int> vec7{-18, -10, -1, -1, -1, 0, 3, 5, 10};
+  std::pair<int, int> ans7{2, 5};
+  ASSERT_EQ(SearchingSum(vec7, sum7), ans7);
+
+  int sum8 = 5;
+  std::vector<int> vec8(0);
+  std::pair<int, int> ans8{-1, -1};
+  ASSERT_EQ(SearchingSum(vec8, sum8), ans8);
 }
diff --git a/task_01/src/topology_sort.cpp b/task_01/src/topology_sort.cpp
deleted file mode 100644
index e53f670c..00000000
--- a/task_01/src/topology_sort.cpp
+++ /dev/null
@@ -1 +0,0 @@
-#include "topology_sort.hpp"
diff --git a/task_01/src/topology_sort.hpp b/task_01/src/topology_sort.hpp
deleted file mode 100644
index 6f70f09b..00000000
--- a/task_01/src/topology_sort.hpp
+++ /dev/null
@@ -1 +0,0 @@
-#pragma once
diff --git a/task_02/src/main.cpp b/task_02/src/main.cpp
index 0e4393ba..7fbe48d8 100644
--- a/task_02/src/main.cpp
+++ b/task_02/src/main.cpp
@@ -1,3 +1,3 @@
-#include <iostream>
+#include "stack.hpp"
 
-int main() { return 0; }
+int main() { Stack<int> stack; }
diff --git a/task_02/src/stack.cpp b/task_02/src/stack.cpp
deleted file mode 100644
index 8ca89902..00000000
--- a/task_02/src/stack.cpp
+++ /dev/null
@@ -1,21 +0,0 @@
-#include "stack.hpp"
-
-#include <algorithm>
-
-void Stack::Push(int value) { data_.push(value); }
-
-int Stack::Pop() {
-  auto result = data_.top();
-  data_.pop();
-  return result;
-}
-
-void MinStack::Push(int value) { data_.push_back(value); }
-
-int MinStack::Pop() {
-  auto result = data_.back();
-  data_.pop_back();
-  return result;
-}
-
-int MinStack::GetMin() { return *std::min_element(data_.begin(), data_.end()); }
\ No newline at end of file
diff --git a/task_02/src/stack.hpp b/task_02/src/stack.hpp
index 138ec40f..ae1df3c0 100644
--- a/task_02/src/stack.hpp
+++ b/task_02/src/stack.hpp
@@ -1,23 +1,107 @@
 #pragma once
 
-#include <stack>
-#include <vector>
+#include <memory>
 
+template <typename T>
+struct Element {
+  explicit Element(T data, std::shared_ptr<Element<T>> prev = nullptr)
+      : element{data}, prev{prev} {}
+
+  explicit Element() : element{}, prev{nullptr} {}
+
+  T element;
+
+  std::shared_ptr<Element<T>> prev;
+};
+
+template <typename T>
 class Stack {
  public:
-  void Push(int value);
-  int Pop();
+  explicit Stack() : data_{} {}
+
+  void Push(T value);
+
+  T Pop();
+
+  bool Empty() const;
+
+  const T& Top() const;
+
+  size_t Size() const;
 
  private:
-  std::stack<int> data_;
+  Element<T> data_;
+
+  size_t size_ = 0;
 };
 
+template <typename T>
+void Stack<T>::Push(T value) {
+  Element new_data{value, std::make_shared<Element<T>>(data_)};
+  size_ += 1;
+  data_ = new_data;
+}
+
+template <typename T>
+T Stack<T>::Pop() {
+  T deleted_element = data_.element;
+  Element new_data = *data_.prev;
+  data_.prev = nullptr;
+  data_ = new_data;
+  size_ -= 1;
+  return deleted_element;
+}
+
+template <typename T>
+bool Stack<T>::Empty() const {
+  return data_.prev == nullptr;
+}
+
+template <typename T>
+const T& Stack<T>::Top() const {
+  return data_.element;
+}
+
+template <typename T>
+size_t Stack<T>::Size() const {
+  return size_;
+}
+
+template <typename T>
 class MinStack {
  public:
-  void Push(int value);
-  int Pop();
-  int GetMin();
+  void Push(T value);
+  T Pop();
+  T GetMin() const;
 
  private:
-  std::vector<int> data_;
+  Stack<T> main_stack_;
+  Stack<T> min_stack_;
 };
+
+template <typename T>
+void MinStack<T>::Push(T value) {
+  if (main_stack_.Size() == 0) {
+    min_stack_.Push(value);
+    main_stack_.Push(value);
+  } else {
+    main_stack_.Push(value);
+    if (value < min_stack_.Top())
+      min_stack_.Push(value);
+    else
+      min_stack_.Push(min_stack_.Top());
+  }
+}
+
+template <typename T>
+T MinStack<T>::Pop() {
+  T result = main_stack_.Top();
+  main_stack_.Pop();
+  min_stack_.Pop();
+  return result;
+}
+
+template <typename T>
+T MinStack<T>::GetMin() const {
+  return min_stack_.Top();
+}
\ No newline at end of file
diff --git a/task_02/src/test.cpp b/task_02/src/test.cpp
index 54e7ce90..eebfa1e4 100644
--- a/task_02/src/test.cpp
+++ b/task_02/src/test.cpp
@@ -1,12 +1,9 @@
-
 #include <gtest/gtest.h>
 
-#include <stack>
-
 #include "stack.hpp"
 
 TEST(StackTest, Simple) {
-  Stack stack;
+  Stack<int> stack;
   stack.Push(1);              // Stack [1]
   ASSERT_EQ(stack.Pop(), 1);  // Stack []
   stack.Push(1);              // Stack [1]
@@ -22,7 +19,7 @@ TEST(StackTest, Simple) {
 }
 
 TEST(MinStackTest, Simple) {
-  MinStack stack;
+  MinStack<int> stack;
   stack.Push(1);  // Stack [1]
   ASSERT_EQ(stack.GetMin(), 1);
   ASSERT_EQ(stack.Pop(), 1);  // Stack []
@@ -39,4 +36,16 @@ TEST(MinStackTest, Simple) {
   ASSERT_EQ(stack.GetMin(), 1);
   ASSERT_EQ(stack.Pop(), 3);  // Stack [1]
   ASSERT_EQ(stack.Pop(), 1);  // Stack []
+  stack.Push(2);              // Stack [2]
+  ASSERT_EQ(stack.GetMin(), 2);
+  stack.Push(7);  // Stack [2, 7]
+  ASSERT_EQ(stack.GetMin(), 2);
+  stack.Push(-2);  // Stack [2, 7, -2]
+  ASSERT_EQ(stack.GetMin(), -2);
+  stack.Push(8);  // Stack [2, 7, -2, 8]
+  ASSERT_EQ(stack.GetMin(), -2);
+  stack.Push(-2);  // Stack [2, 7, -2, 8, -2]
+  ASSERT_EQ(stack.GetMin(), -2);
+  ASSERT_EQ(stack.Pop(), -2);  // Stack [2, 7, -2, 8]
+  ASSERT_EQ(stack.GetMin(), -2);
 }
\ No newline at end of file
diff --git a/task_03/src/main.cpp b/task_03/src/main.cpp
index 0e4393ba..a46533a9 100644
--- a/task_03/src/main.cpp
+++ b/task_03/src/main.cpp
@@ -1,3 +1,3 @@
-#include <iostream>
+#include "temperature.hpp"
 
 int main() { return 0; }
diff --git a/task_03/src/temperature.cpp b/task_03/src/temperature.cpp
new file mode 100644
index 00000000..d78b7011
--- /dev/null
+++ b/task_03/src/temperature.cpp
@@ -0,0 +1,19 @@
+#include "temperature.hpp"
+
+#include <stack>
+#include <vector>
+
+std::vector<int> days_before_warming(std::vector<int> daily_temp) {
+  std::vector<int> days_amount(daily_temp.size());
+  std::stack<int> previous_days;
+  for (int day_index = 0; day_index < daily_temp.size(); ++day_index) {
+    days_amount[day_index] = 0;
+    while (!previous_days.empty() &&
+           daily_temp[previous_days.top()] <= daily_temp[day_index]) {
+      days_amount[previous_days.top()] = day_index - previous_days.top();
+      previous_days.pop();
+    }
+    previous_days.push(day_index);
+  }
+  return days_amount;
+}
\ No newline at end of file
diff --git a/task_03/src/temperature.hpp b/task_03/src/temperature.hpp
new file mode 100644
index 00000000..c0e2c0a5
--- /dev/null
+++ b/task_03/src/temperature.hpp
@@ -0,0 +1,3 @@
+#include <vector>
+
+std::vector<int> days_before_warming(std::vector<int> daily_temp);
\ No newline at end of file
diff --git a/task_03/src/test.cpp b/task_03/src/test.cpp
index ef5a86ae..24dfa245 100644
--- a/task_03/src/test.cpp
+++ b/task_03/src/test.cpp
@@ -1,8 +1,33 @@
-
 #include <gtest/gtest.h>
 
-#include "topology_sort.hpp"
+#include <cstddef>
+
+#include "temperature.hpp"
+
+TEST(temperature, Simple) {
+  std::vector<int> daily_temp_1 = days_before_warming({1, 2, 3, 4, 5});
+  std::vector<int> result_1 = {1, 1, 1, 1, 0};
+  ASSERT_EQ(daily_temp_1, result_1);
+
+  std::vector<int> daily_temp_2 = days_before_warming({0});
+  std::vector<int> result_2 = {0};
+  ASSERT_EQ(daily_temp_2, result_2);
+
+  std::vector<int> daily_temp_3 = days_before_warming({});
+  std::vector<int> result_3 = {};
+  ASSERT_EQ(daily_temp_3, result_3);
+
+  std::vector<int> daily_temp_4 =
+      days_before_warming({1, 2, -4, -5, -6, -8, 9});
+  std::vector<int> result_4 = {1, 5, 4, 3, 2, 1, 0};
+  ASSERT_EQ(daily_temp_4, result_4);
+
+  std::vector<int> daily_temp_5 = days_before_warming({1, 2, 1, 2, 1, 2, 1, 2});
+  std::vector<int> result_5 = {1, 2, 1, 2, 1, 2, 1, 0};
+  ASSERT_EQ(daily_temp_5, result_5);
 
-TEST(TopologySort, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
-}
+  std::vector<int> daily_temp_6 =
+      days_before_warming({2, 1, 3, 1, 4, 1, 3, 1, 2, 1, 5});
+  std::vector<int> result_6 = {2, 1, 2, 1, 6, 1, 4, 1, 2, 1, 0};
+  ASSERT_EQ(daily_temp_6, result_6);
+}
\ No newline at end of file
diff --git a/task_03/src/topology_sort.cpp b/task_03/src/topology_sort.cpp
deleted file mode 100644
index e53f670c..00000000
--- a/task_03/src/topology_sort.cpp
+++ /dev/null
@@ -1 +0,0 @@
-#include "topology_sort.hpp"
diff --git a/task_03/src/topology_sort.hpp b/task_03/src/topology_sort.hpp
deleted file mode 100644
index 6f70f09b..00000000
--- a/task_03/src/topology_sort.hpp
+++ /dev/null
@@ -1 +0,0 @@
-#pragma once