code: добавлен параматер promt

histogram.cpp

@@ -1,20 +1,31 @@
 #include <vector>
 #include "histogram.h"
 using namespace std;
-void find_minmax(const vector<double>& numbers, double& min, double& max)
-{
-    min = numbers[0];
-    max = numbers[0];
-    for (double x : numbers) {
-        if (x < min) {
-            min = x;
-        }
-        else if (x > max) {
-            max = x;
+
+bool
+find_minmax(const std::vector<double>& numbers, double& min, double& max){
+    if (numbers.size() != 0) {
+        min = numbers[0];
+        max = numbers[0];
+
+        for (double x : numbers) {
+            if (x < min) {
+                min = x;
+            }
+            else if (x > max) {
+                max = x;
+            }
         }
+        return true;
+    }
+
+    else {
+        return false;
     }
+
 }
 
+
 vector<size_t> make_histogram(const vector<double>& numbers, size_t bin_count)
 {
     double min,max;

histogram_internal.h

@@ -1,6 +1,6 @@
 #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 find_minmax(const std::vector<double>& numbers, double& min, double& max);
 
 #endif // HISTOGRAM_INTERNAL_H_INCLUDED

main.cpp

@@ -10,28 +10,44 @@ struct Input{
     size_t bin_count{};
 };
 
-Input input_data()
+Input input_data(istream& in, bool promt)
 {
-    size_t number_count;
-    cerr << "Enter number count: ";
-    cin >> number_count;
+    if (promt){
+        size_t number_count;
+        cerr << "Enter number count: ";
+        in >> number_count;
 
-    Input in;
+        Input In;
 
-    in.numbers.resize(number_count);
-    cerr << "Enter numbers: ";
-    for(size_t i = 0; i < number_count; i++){
-        cin >> in.numbers[i];
+        In.numbers.resize(number_count);
+        cerr << "Enter numbers: ";
+        for(size_t i = 0; i < number_count; i++){
+            in >> In.numbers[i];
+        }
+
+        cerr << "Enter bin count: ";
+        in >> In.bin_count;
+        return In;
     }
+    else{
+        size_t number_count;
+        in >> number_count;
+
+        Input In;
 
-    cerr << "Enter bin count: ";
-    cin >> in.bin_count;
-    return in;
+        In.numbers.resize(number_count);
+        for(size_t i = 0; i < number_count; i++){
+            in >> In.numbers[i];
+        }
+
+        in >> In.bin_count;
+        return In;
+    }
 }
 
 int main()
 {
-    auto in = input_data();
+    auto in = input_data(cin,false);
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins);
     return 0;

svg.cpp

@@ -2,7 +2,6 @@
 #include <iostream>
 #include <vector>
 #include <string>
-const size_t x=20;
 using namespace std;
 
 void
@@ -35,7 +34,7 @@ void
 show_histogram_svg(const vector<size_t>& bins) {
     const auto IMAGE_WIDTH = 400;
     const auto IMAGE_HEIGHT = 300;
-    const auto TEXT_LEFT = IMAGE_WIDTH-30;
+    const auto TEXT_LEFT = 20;
     const auto TEXT_BASELINE = 20;
     const auto TEXT_WIDTH = 50;
     const auto BIN_HEIGHT = 30;
@@ -54,7 +53,7 @@ show_histogram_svg(const vector<size_t>& bins) {
         for (size_t bin : bins) {
             const double bin_width = space * bin / max_count;
             svg_text(TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));
-            svg_rect(TEXT_LEFT - bin_width - 20, top, bin_width, BIN_HEIGHT, "black", "blue");
+            svg_rect(TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", "blue");
             top += BIN_HEIGHT;
         }
         svg_end();
@@ -63,7 +62,7 @@ show_histogram_svg(const vector<size_t>& bins) {
         for (size_t bin : bins) {
             const double bin_width = BLOCK_WIDTH * bin;
             svg_text(TEXT_LEFT, top + TEXT_BASELINE, to_string(bin));
-            svg_rect(TEXT_LEFT - bin_width - 20, top, bin_width, BIN_HEIGHT, "black", "blue");
+            svg_rect(TEXT_WIDTH, top, bin_width, BIN_HEIGHT, "black", "blue");
             top += BIN_HEIGHT;
         }
         svg_end();

unittest.cpp

@@ -4,9 +4,40 @@
 #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("negative numbers") {
     double min = 0;
     double max = 0;
     find_minmax({-1, -2 , -5}, min, max);
-    CHECK(min == -3);
+    CHECK(min == -5);
     CHECK(max == -1);
 }
+
+TEST_CASE("one number") {
+    double min = 0;
+    double max = 0;
+    find_minmax({1}, min, max);
+    CHECK(min == 1);
+    CHECK(max == 1);
+}
+
+TEST_CASE("equal elements") {
+    double min = 0;
+    double max = 0;
+    find_minmax({1,1,1,1}, min, max);
+    CHECK(min == 1);
+    CHECK(max == 1);
+}
+
+TEST_CASE("zero vector") {
+    double min = 0;
+    double max = 0;
+    CHECK(!find_minmax({}, min, max));
+}
+