3. разделение на файлы

histogram.cpp

@@ -0,0 +1,50 @@
+#include "histogram.h"
+#include "histogram_internal.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;
+        }
+    }
+}
+
+
+vector<size_t> make_histogram(const vector<double> &numbers, size_t bin_count)
+{
+    double min, max;
+    find_minmax(numbers, min, max);
+    double bin_size = (max - min) / bin_count;
+    vector <size_t> bins (bin_count);
+
+    for (size_t i = 0; i < numbers.size(); i++)
+    {
+        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 <= numbers[i]) && (numbers[i] < hi))
+            {
+                bins[j]++;
+                found = true;
+            }
+        }
+        if (!found)
+        {
+            bins[bin_count - 1]++;
+        }
+    }
+    return bins;
+}