diff --git a/task_01/src/main.cpp b/task_01/src/main.cpp
index 0e4393ba..4c7e26e5 100644
--- a/task_01/src/main.cpp
+++ b/task_01/src/main.cpp
@@ -1,3 +1,17 @@
 #include <iostream>
 
-int main() { return 0; }
+#include "summandds_in_array.hpp"
+
+int main() {
+  int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+  int m = 5;
+  std::optional<std::tuple<int*, int*>> b = SummanddsInArray(a, 9, m);
+  if (b) {
+    std::cout << "found" << std::endl;
+    std::cout << std::get<0>(b.value()) << " : " << *std::get<0>(b.value())
+              << std::endl;
+    std::cout << std::get<1>(b.value()) << " : " << *std::get<1>(b.value())
+              << std::endl;
+  } else
+    std::cout << "NOT found" << std::endl;
+}
diff --git a/task_01/src/summandds_in_array.cpp b/task_01/src/summandds_in_array.cpp
new file mode 100644
index 00000000..15ad2457
--- /dev/null
+++ b/task_01/src/summandds_in_array.cpp
@@ -0,0 +1,21 @@
+#include "summandds_in_array.hpp"
+
+#include <optional>
+
+std::optional<std::tuple<int *, int *>> SummanddsInArray(int *arr, int n,
+                                                         int sum) {
+  int *begin = arr;
+  int *end = arr + (n - 1);
+  while (begin && end && begin < end && *begin + *end != sum)
+    if ((*begin + *end) > sum)
+      end--;
+    else
+      begin++;
+  if ((!begin) || (!end) || (begin >= end) || (*begin + *end != sum))
+    begin = end = nullptr;
+
+  std::optional<std::tuple<int *, int *>> result = std::nullopt;
+  if (begin != nullptr && end != nullptr)
+    result = std::tuple<int *, int *>{begin, end};
+  return result;
+}
diff --git a/task_01/src/summandds_in_array.hpp b/task_01/src/summandds_in_array.hpp
new file mode 100644
index 00000000..c3801ac6
--- /dev/null
+++ b/task_01/src/summandds_in_array.hpp
@@ -0,0 +1,9 @@
+#ifndef SUMMANDDS_IN_ARRAY_HPP
+#define SUMMANDDS_IN_ARRAY_HPP
+
+#include <optional>
+#include <tuple>
+
+std::optional<std::tuple<int*, int*>> SummanddsInArray(int* arr, int n, int m);
+
+#endif
\ No newline at end of file
diff --git a/task_01/src/test.cpp b/task_01/src/test.cpp
index ef5a86ae..09e953b2 100644
--- a/task_01/src/test.cpp
+++ b/task_01/src/test.cpp
@@ -1,8 +1,97 @@
 
 #include <gtest/gtest.h>
 
-#include "topology_sort.hpp"
+#include "summandds_in_array.hpp"
 
-TEST(TopologySort, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
+TEST(SummanddsInArray, Simple1) {
+  int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+  int n = 9;
+  int m = 11;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_TRUE(a);
+  ASSERT_EQ(*std::get<0>(a.value()) + *std::get<1>(a.value()), m);
 }
+
+TEST(SummanddsInArray, Simple2) {
+  int arr[] = {1, 2, 3, 4, 5, 8, 9};
+  int n = 7;
+  int m = 5;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_TRUE(a);
+  ASSERT_EQ(*std::get<0>(a.value()) + *std::get<1>(a.value()), m);
+}
+TEST(SummanddsInArray, Simple3) {
+  int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
+  int n = 9;
+  int m = 3;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_TRUE(a);
+  ASSERT_EQ(*std::get<0>(a.value()) + *std::get<1>(a.value()), m);
+}
+
+TEST(SummanddsInArray, Simple4) {
+  int arr[] = {1, 3, 5, 7, 9};
+  int n = 5;
+  int m = 7;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
+
+TEST(SummanddsInArray, Nullarr) {
+  int* arr = nullptr;
+  int n = 9;
+  int m = 3;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
+
+TEST(SummanddsInArray, Specific1) {
+  int arr_ref[] = {10, 2, 3, 4, 5, 5, 7, 8, 0};
+  int* arr = arr_ref + 1;
+  int n = 9;
+  int m = 5;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_TRUE(a);
+  ASSERT_EQ(*std::get<0>(a.value()) + *std::get<1>(a.value()), m);
+}
+
+TEST(SummanddsInArray, Specific2) {
+  int arr[] = {1, 2, 4, 5, 8};
+  int n = 5;
+  int m = 8;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
+
+TEST(SummanddsInArray, Specific3) {
+  int arr[] = {1, 3, 4, 5, 8};
+  int n = 5;
+  int m = 16;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
+
+TEST(SummanddsInArray, Specific4) {
+  int arr[] = {1, 3, 4, 5, 5, 8};
+  int n = 6;
+  int m = 10;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_TRUE(a);
+  ASSERT_EQ(*std::get<0>(a.value()) + *std::get<1>(a.value()), m);
+}
+
+TEST(SummanddsInArray, Specific5) {
+  int arr[] = {};
+  int n = 0;
+  int m = 10;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
+
+TEST(SummanddsInArray, Specific6) {
+  int arr[] = {10};
+  int n = 1;
+  int m = 20;
+  std::optional<std::tuple<int*, int*>> a = SummanddsInArray(arr, n, m);
+  ASSERT_FALSE(a);
+}
\ No newline at end of file
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