diff --git a/Lab01.cbp b/Lab01.cbp
index 5d67df3..fafc2c3 100644
--- a/Lab01.cbp
+++ b/Lab01.cbp
@@ -39,6 +39,7 @@
 		<Unit filename="text.cpp" />
 		<Unit filename="text.h" />
 		<Unit filename="unittest.cbp" />
+		<Unit filename="unittest.cpp" />
 		<Extensions />
 	</Project>
 </CodeBlocks_project_file>
diff --git a/doctest.h b/doctest.h
index 6f43ce0..5c754cd 100644
--- a/doctest.h
+++ b/doctest.h
@@ -7104,4 +7104,3 @@ DOCTEST_SUPPRESS_COMMON_WARNINGS_POP
 #undef NOMINMAX
 #undef DOCTEST_UNDEF_NOMINMAX
 #endif // DOCTEST_UNDEF_NOMINMAX
-
diff --git a/histogram.cpp b/histogram.cpp
index 6477f85..a54fe18 100644
--- a/histogram.cpp
+++ b/histogram.cpp
@@ -1,7 +1,12 @@
 #include "histogram.h"
 #include <vector>
-void find_minmax(const std::vector <double> &numbers, double &min, double &max)
+void find_minmax(const std::vector <double> &numbers, double &min, double &max, bool &res)
 {
+    if (numbers.size()==0)
+    {
+        res = true;
+        return;
+    }
     min = numbers[0];
     max = numbers[0];
     for (double x : numbers)
@@ -19,7 +24,8 @@ void find_minmax(const std::vector <double> &numbers, double &min, double &max)
 std::vector<std::size_t> make_histogram(const std::vector<double> &numbers, std::size_t bin_count)
 {
     double min, max;
-    find_minmax(numbers, min, max);
+    bool res = false;
+    find_minmax(numbers, min, max, res);
     double bin_size = (max - min) / bin_count;
     std::vector <std::size_t> bins (bin_count);
 
diff --git a/main.cpp b/main.cpp
index 8883021..f29ddf9 100644
--- a/main.cpp
+++ b/main.cpp
@@ -29,6 +29,7 @@ input_data()
 int
 main()
 {
+    bool res = false;
     Input in = input_data();
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_text(bins);
diff --git a/text.cpp b/text.cpp
index 34c7d59..5edd2ec 100644
--- a/text.cpp
+++ b/text.cpp
@@ -8,6 +8,7 @@ const std::size_t MAX_ASTERISK = SCREEN_WIDTH - 3 - 1;
 void
 show_histogram_text(const std::vector <std::size_t> &bins)
 {
+    std::cout<<std::endl;
     std::size_t max_count = bins[0];
     for (std::size_t i = 0; i < bins.size(); i++)
     {
diff --git a/unittest.cpp b/unittest.cpp
index a9ba7e5..52652b5 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -3,10 +3,65 @@
 #include "doctest.h"
 #include "histogram_internal.h"
 
+
+
 TEST_CASE("distinct positive numbers") {
+    bool res = false;
     double min = 0;
     double max = 0;
-    find_minmax({1, 2}, min, max);
+    find_minmax({1, 2}, min, max, res);
     CHECK(min == 1);
     CHECK(max == 2);
+    CHECK(res==0);
+}
+
+TEST_CASE("negative numbers") {
+    bool res = false;
+    double min = 0;
+    double max = 0;
+    find_minmax({-1, -2}, min, max, res);
+    CHECK(min == -2);
+    CHECK(max == -1);
+    CHECK(res==0);
+}
+
+TEST_CASE("empty array") {
+    bool res = false;
+    double min = 0;
+    double max = 0;
+    std::vector<double> numbers;
+    find_minmax(numbers, min, max, res);
+    CHECK(min == 0);
+    CHECK(max == 0);
+    CHECK(res==1);
+}
+
+TEST_CASE("1 number") {
+    bool res = false;
+    double min = 0;
+    double max = 0;
+    find_minmax({-1}, min, max, res);
+    CHECK(min == -1);
+    CHECK(max == -1);
+    CHECK(res==0);
+}
+
+TEST_CASE("same number") {
+    bool res = false;
+    double min = 0;
+    double max = 0;
+    find_minmax({1,1,1,1}, min, max, res);
+    CHECK(min == 1);
+    CHECK(max == 1);
+    CHECK(res==0);
+}
+
+TEST_CASE("same number but zero") {
+    bool res = false;
+    double min = 0;
+    double max = 0;
+    find_minmax({0,0,0,0}, min, max, res);
+    CHECK(min == 0);
+    CHECK(max == 0);
+    CHECK(res==0);
 }