diff --git a/histogram.cpp b/histogram.cpp
index cf4a912..ce7a325 100644
--- a/histogram.cpp
+++ b/histogram.cpp
@@ -1,6 +1,6 @@
 #include "histogram.h"
 
-void find_minmax(std::vector<double>& vec, double& min, double& max) {
+void find_minmax(std::vector<double> vec, double& min, double& max) {
 
 
     min = vec[0];
@@ -11,8 +11,8 @@ void find_minmax(std::vector<double>& vec, double& min, double& max) {
     }
 }
 
-std::vector<size_t> make_histogram(size_t number, std::vector<double>& vec) {
-    std::vector<size_t> bins(number);
+vector<size_t> make_histogram(size_t number, vector<double> vec) {
+    vector<size_t> bins(number);
     if (vec.empty()) return bins;
 
     double mn, mx;
diff --git a/histogram.h b/histogram.h
index 8d2cfd4..fc94053 100644
--- a/histogram.h
+++ b/histogram.h
@@ -4,6 +4,7 @@
 #include <vector>
 #include <iostream>
 
-std::vector<size_t> make_histogram(size_t number, std::vector<double>& vec);
+using namespace std;
+vector<size_t> make_histogram(size_t number, vector<double> vec);
 
 #endif // HISTOGRAM_H_INCLUDED
diff --git a/histogram_internal.h b/histogram_internal.h
index 5bbe4ff..4567891 100644
--- a/histogram_internal.h
+++ b/histogram_internal.h
@@ -1,6 +1,6 @@
 #ifndef HISTOGRAM_INTERNAL_H_INCLUDED
 #define HISTOGRAM_INTERNAL_H_INCLUDED
 
-void find_minmax(std::vector<double>& vec, double& min, double& max);
+void find_minmax(std::vector<double> vec, double& min, double& max);
 
 #endif // HISTOGRAM_INTERNAL_H_INCLUDED
diff --git a/text.cpp b/text.cpp
index 3ca4555..add972a 100644
--- a/text.cpp
+++ b/text.cpp
@@ -1,7 +1,7 @@
 #include "text.h"
 #include <iostream>
 
-void show_histogram(const std::vector<size_t>& bins) {
+void show_histogram(const vector<size_t>& bins) {
 
 
     bool gigant = false;
diff --git a/text.h b/text.h
index f1c59f4..df05754 100644
--- a/text.h
+++ b/text.h
@@ -3,6 +3,6 @@
 
 #include <vector>
 
-void show_histogram(const std::vector<size_t>& bins);
+void show_histogram(const vector<size_t>& bins);
 
 #endif // TEXT_H_INCLUDED
diff --git a/unittest.cpp b/unittest.cpp
index e69de29..37074ec 100644
--- a/unittest.cpp
+++ b/unittest.cpp
@@ -0,0 +1,55 @@
+#define DOCTEST_CONFIG_NO_MULTITHREADING
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+#include "doctest.h"
+#include "histogram_internal.h"
+
+TEST_CASE("distinct positive numbers") {
+    double min = 0;
+    double max = 0;
+    find_minmax({1, 2}, min, max);
+    CHECK(min == 1);
+    CHECK(max == 2);
+}
+TEST_CASE("distinct negative numbers"){
+    double min = 0;
+    double max = 0;
+    find_minmax({-1, -2}, min, max);
+    CHECK(min == -2);
+    CHECK(max == -1);
+}
+TEST_CASE("vector of the same elements"){
+    double min = 0;
+    double max = 0;
+    find_minmax({3,3,3}, min, max);
+    CHECK(min == 3);
+    CHECK(max == 3);
+}
+TEST_CASE("vector of one elements"){
+    double min = 0;
+    double max = 0;
+    find_minmax({3}, min, max);
+    CHECK(min == max);
+}
+TEST_CASE("mixed positive and negative numbers") {
+    double min = 0;
+    double max = 0;
+    find_minmax({-1, 2, 0, -3, 5}, min, max);
+    CHECK(min == -3);
+    CHECK(max == 5);
+}
+
+TEST_CASE("vector with all negative numbers") {
+    double min = 0;
+    double max = 0;
+    find_minmax({-5, -10, -2}, min, max);
+    CHECK(min == -10);
+    CHECK(max == -2);
+}
+
+TEST_CASE("vector with zero") {
+    double min = 0;
+    double max = 0;
+    find_minmax({0, -1, 1}, min, max);
+    CHECK(min == -1);
+    CHECK(max == 1);
+}
diff --git a/unittest/bin/Debug/unittest.exe b/unittest/bin/Debug/unittest.exe
new file mode 100644
index 0000000..d854462
Binary files /dev/null and b/unittest/bin/Debug/unittest.exe differ
diff --git a/unittest/obj/Debug/histogram.o b/unittest/obj/Debug/histogram.o
index efab4b0..e1f6ebb 100644
Binary files a/unittest/obj/Debug/histogram.o and b/unittest/obj/Debug/histogram.o differ
diff --git a/unittest/obj/Debug/unittest.o b/unittest/obj/Debug/unittest.o
index d7e28df..51853c6 100644
Binary files a/unittest/obj/Debug/unittest.o and b/unittest/obj/Debug/unittest.o differ
diff --git a/unittest/unittest.depend b/unittest/unittest.depend
new file mode 100644
index 0000000..0627a11
--- /dev/null
+++ b/unittest/unittest.depend
@@ -0,0 +1,59 @@
+# depslib dependency file v1.0
+1748213255 source:c:\users\home\desktop\lab34\laba01\histogram.cpp
+	"histogram.h"
+
+1748213210 c:\users\home\desktop\lab34\laba01\histogram.h
+	<vector>
+	<iostream>
+
+1748213127 source:c:\users\home\desktop\lab34\laba01\unittest.cpp
+	"doctest.h"
+	"histogram_internal.h"
+
+1748211324 c:\users\home\desktop\lab34\laba01\doctest.h
+	<signal.h>
+	<ciso646>
+	<cstddef>
+	<ostream>
+	<istream>
+	<type_traits>
+	"doctest_fwd.h"
+	<ctime>
+	<cmath>
+	<climits>
+	<math.h>
+	<new>
+	<cstdio>
+	<cstdlib>
+	<cstring>
+	<limits>
+	<utility>
+	<fstream>
+	<sstream>
+	<iostream>
+	<algorithm>
+	<iomanip>
+	<vector>
+	<atomic>
+	<mutex>
+	<set>
+	<map>
+	<unordered_set>
+	<exception>
+	<stdexcept>
+	<csignal>
+	<cfloat>
+	<cctype>
+	<cstdint>
+	<string>
+	<sys/types.h>
+	<unistd.h>
+	<sys/sysctl.h>
+	<AfxWin.h>
+	<windows.h>
+	<io.h>
+	<sys/time.h>
+	<unistd.h>
+
+1748213259 c:\users\home\desktop\lab34\laba01\histogram_internal.h
+