code: модульные тесты; улучшены функции с расчетом и печатью гистограммы для работы с пустым вектором

histogram.cpp

@@ -2,20 +2,27 @@
 
 using namespace std;
 
-static void
-find_minmax(const vector<double>& numbers, double& min, double& max)
+void
+find_minmax(const vector<double>& numbers, double& min, double& max, bool& empty_vector)
 {
-    min = numbers[0];
-    max = numbers[0];
-    for (double x : numbers)
+    if (numbers.empty())
     {
-        if (x > max )
+        empty_vector = true;
+    }
+    else
+    {
+        min = numbers[0];
+        max = numbers[0];
+        for (double x : numbers)
         {
-            max = x;
-        }
-        if (x < min)
-        {
-            min = x;
+            if (x > max )
+            {
+                max = x;
+            }
+            if (x < min)
+            {
+                min = x;
+            }
         }
     }
 }
@@ -25,25 +32,36 @@ make_histogram(const vector<double>& numbers, size_t& bin_count)
 {
     double min = 0;
     double max = 0;
-    find_minmax(numbers, min, max);
-    auto bin_size = (max - min)/bin_count;
+    bool empty_vector = false;
+    find_minmax(numbers, min, max, empty_vector);
     vector<size_t> bins(bin_count);
-    for (double number : numbers)
+    if (empty_vector)
     {
-        bool found = false;
-        for (size_t j = 0; (j < bin_count - 1) && !found; j++)
+        for (size_t y : bins)
         {
-            auto lo = min + j * bin_size;
-            auto hi = min + (j + 1) * bin_size;
-            if ((lo <= number) && (number < hi))
-            {
-                bins[j]++;
-                found = true;
-            }
+            y = 0;
         }
-        if (!found)
+    }
+    else
+    {
+        auto bin_size = (max - min)/bin_count;
+        for (double number : numbers)
         {
-            bins[bin_count - 1]++;
+            bool found = false;
+            for (size_t j = 0; (j < bin_count - 1) && !found; j++)
+            {
+                auto lo = min + j * bin_size;
+                auto hi = min + (j + 1) * bin_size;
+                if ((lo <= number) && (number < hi))
+                {
+                    bins[j]++;
+                    found = true;
+                }
+            }
+            if (!found)
+            {
+                bins[bin_count - 1]++;
+            }
         }
     }
     return bins;

histogram_internal.h

@@ -0,0 +1,9 @@
+#ifndef HISTOGRAM_INTERNAL_H_INCLUDED
+#define HISTOGRAM_INTERNAL_H_INCLUDED
+
+#include <vector>
+
+void
+find_minmax(const std::vector<double>& numbers, double& min, double& max, bool& empty_vector);
+
+#endif // HISTOGRAM_INTERNAL_H_INCLUDED

lab01.cbp

@@ -36,7 +36,14 @@
 		<Unit filename="histogram.h">
 			<Option target="&lt;{~None~}&gt;" />
 		</Unit>
+		<Unit filename="histogram_internal.h">
+			<Option target="&lt;{~None~}&gt;" />
+		</Unit>
 		<Unit filename="main.cpp" />
+		<Unit filename="text.cpp" />
+		<Unit filename="text.h">
+			<Option target="&lt;{~None~}&gt;" />
+		</Unit>
 		<Extensions>
 			<lib_finder disable_auto="1" />
 		</Extensions>

text.cpp

@@ -4,7 +4,8 @@
 using namespace std;
 
 void
-show_histogram_text(const vector<size_t>& bins, size_t& bin_count) {
+show_histogram_text(const vector<size_t>& bins, size_t& bin_count)
+{
     const size_t SCREEN_WIDTH = 80;
     const size_t MAX_ASTERISK = SCREEN_WIDTH - 3 - 1;
     size_t max_count = 0;
@@ -15,6 +16,10 @@ show_histogram_text(const vector<size_t>& bins, size_t& bin_count) {
             max_count = bins[s];
         }
     }
+    if (max_count == 0)
+    {
+        max_count = 1;
+    }
     auto scale_factor = static_cast<double>(MAX_ASTERISK) / max_count;
     if (scale_factor > 1)
     {

unittest.cpp

@@ -0,0 +1,54 @@
+#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;
+    bool empty_vector = false;
+    find_minmax({1, 2}, min, max, empty_vector);
+    CHECK(empty_vector == false);
+    CHECK(min == 1);
+    CHECK(max == 2);
+}
+
+TEST_CASE("the only number") {
+    double min = 0;
+    double max = 0;
+    bool empty_vector = false;
+    find_minmax({1}, min, max, empty_vector);
+    CHECK(empty_vector == false);
+    CHECK(min == 1);
+    CHECK(max == 1);
+}
+
+TEST_CASE("negative numbers") {
+    double min = 0;
+    double max = 0;
+    bool empty_vector = false;
+    find_minmax({-1, -2}, min, max, empty_vector);
+    CHECK(empty_vector == false);
+    CHECK(min == -2);
+    CHECK(max == -1);
+}
+
+TEST_CASE("identical numbers") {
+    double min = 0;
+    double max = 0;
+    bool empty_vector = false;
+    find_minmax({2, 2}, min, max, empty_vector);
+    CHECK(empty_vector == false);
+    CHECK(min == 2);
+    CHECK(max == 2);
+}
+
+TEST_CASE("empty vector") {
+    double min = 0;
+    double max = 0;
+    bool empty_vector = false;
+    find_minmax({}, min, max, empty_vector);
+    CHECK(empty_vector == true);
+    CHECK(min == 0);
+    CHECK(max == 0);
+}