diff --git a/task_01/src/main.cpp b/task_01/src/main.cpp
index 0e4393b..488bcd8 100644
--- a/task_01/src/main.cpp
+++ b/task_01/src/main.cpp
@@ -1,3 +1,12 @@
+#include "mediana.h"
 #include <iostream>
 
-int main() { return 0; }
+int main() {
+    double a;
+    double b;
+    double c;
+    std::cin>>a>>b>>c;
+    double result = mediana(a, b, c);
+    std::cout<<result;
+    return 0;
+}
\ No newline at end of file
diff --git a/task_01/src/mediana.cpp b/task_01/src/mediana.cpp
new file mode 100644
index 0000000..9ad2e4c
--- /dev/null
+++ b/task_01/src/mediana.cpp
@@ -0,0 +1,15 @@
+#include "mediana.h"
+#include <vector>
+double mediana(double a, double b, double c) {
+    double max_value = {a};
+    double min_value = {a};
+    std::vector numbers = {a, b, c};
+    for(auto &x: numbers) {
+        if (x < min_value)
+            min_value = x;
+        if (x>max_value)
+            max_value = x;
+    }
+    double mediana_value = a + b + c - min_value - max_value;
+    return mediana_value;
+}
diff --git a/task_01/src/mediana.h b/task_01/src/mediana.h
new file mode 100644
index 0000000..4f576f2
--- /dev/null
+++ b/task_01/src/mediana.h
@@ -0,0 +1,2 @@
+#pragma once
+double mediana(double a, double b, double c);
diff --git a/task_01/src/test.cpp b/task_01/src/test.cpp
index 0c33b55..27d9261 100644
--- a/task_01/src/test.cpp
+++ b/task_01/src/test.cpp
@@ -1,5 +1,14 @@
 #include <gtest/gtest.h>
+#include "mediana.h"
+
+TEST(Test, Simple) {
+    ASSERT_EQ(mediana(1, 2, 3), 2);
+    ASSERT_EQ(mediana(4, 5, 4.4), 4.4);
+    ASSERT_EQ(mediana(34, 2, 676), 34);
+    ASSERT_EQ(mediana(0, 0, 0), 0);
+    ASSERT_EQ(mediana(1, -6, -5), -5);
+
+}
+
 
-#include <sum.hpp>
 
-TEST(Test, Simple) { ASSERT_EQ(Sum(1, 2, 3), 6); }
\ No newline at end of file
diff --git a/task_02/src/main.cpp b/task_02/src/main.cpp
index 0e4393b..e69de29 100644
--- a/task_02/src/main.cpp
+++ b/task_02/src/main.cpp
@@ -1,3 +0,0 @@
-#include <iostream>
-
-int main() { return 0; }
diff --git a/task_02/src/maximum.cpp b/task_02/src/maximum.cpp
new file mode 100644
index 0000000..68b22aa
--- /dev/null
+++ b/task_02/src/maximum.cpp
@@ -0,0 +1,10 @@
+#include "maximum.h"
+
+double maximum(double *ptr, const int size) {
+    double maximum = *ptr;
+    for(auto i{1}; i < size; i++) {
+        if (maximum < *(ptr + i))
+            maximum = *(ptr + i);
+    }
+    return maximum;
+}
\ No newline at end of file
diff --git a/task_02/src/maximum.h b/task_02/src/maximum.h
new file mode 100644
index 0000000..d6edd69
--- /dev/null
+++ b/task_02/src/maximum.h
@@ -0,0 +1,3 @@
+#pragma once
+
+double maximum(double *ptr, int size);
diff --git a/task_02/src/test.cpp b/task_02/src/test.cpp
index 87cef73..80b550c 100644
--- a/task_02/src/test.cpp
+++ b/task_02/src/test.cpp
@@ -1,5 +1,12 @@
 #include <gtest/gtest.h>
+#include "maximum.h"
+
+double sp[] {1, 23 ,4, 234, 34, 4322, 0, -14};
+double *ptr = {sp};
 
 TEST(Test, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
-}
\ No newline at end of file
+    ASSERT_EQ(maximum(ptr,3), 23);
+    ASSERT_EQ(maximum(ptr,30), 4322);
+    ASSERT_EQ(maximum(ptr,1), 1);
+    ASSERT_EQ(maximum(ptr,5), 234);
+}
diff --git a/task_03/src/main.cpp b/task_03/src/main.cpp
index 76e8197..e69de29 100644
--- a/task_03/src/main.cpp
+++ b/task_03/src/main.cpp
@@ -1 +0,0 @@
-int main() { return 0; }
diff --git a/task_03/src/reverse.cpp b/task_03/src/reverse.cpp
index 3457424..d595739 100644
--- a/task_03/src/reverse.cpp
+++ b/task_03/src/reverse.cpp
@@ -1,3 +1,9 @@
 #include "reverse.hpp"
 
-void Reverse(int *array, size_t len) {}
\ No newline at end of file
+void Reverse(double *array, int len) {
+    for(auto i{0}; int(i<len/2); i++) {
+        double old_el = array[i];
+        array[i] = array[len - i - 1];
+        array[len - i - 1] = old_el;
+    }
+}
\ No newline at end of file
diff --git a/task_03/src/reverse.hpp b/task_03/src/reverse.hpp
index 450a729..a452451 100644
--- a/task_03/src/reverse.hpp
+++ b/task_03/src/reverse.hpp
@@ -1,5 +1,3 @@
 #pragma once
 
-#include <cstddef>
-
-void Reverse(int *array, size_t len);
+void Reverse(double *array, int len);
diff --git a/task_03/src/test.cpp b/task_03/src/test.cpp
index 2d868db..e57c9e1 100644
--- a/task_03/src/test.cpp
+++ b/task_03/src/test.cpp
@@ -1,6 +1,21 @@
-
+#include <ranges>
 #include <gtest/gtest.h>
 
 #include "reverse.hpp"
 
-TEST(Reverse, Simple) {}
+double sp[] {1, 23, 4, 234, 34, 4322, 0, -14};
+double sp_mod[] {-14, 0, 4322, 34, 234, 4, 23, 1};
+double sp2[] {1, 23, 4, 5, 7};
+double sp_mod2[] {7, 5, 4, 23, 1};
+
+
+TEST(Reverse, Simple) {
+    Reverse(sp, 8);
+    for (int i{0}; i < 8; i++) {
+        ASSERT_EQ(sp[i], sp_mod[i]);
+    }
+    Reverse(sp2, 5);
+    for (int i{0}; i < 5; i++) {
+        ASSERT_EQ(sp2[i], sp_mod2[i]);
+    }
+}