пункт 4. Добавила histogram. cpp и histogram_internal.h

histogram.cpp

@@ -0,0 +1,46 @@
+#include "histogram.h"
+#include <vector>
+
+void
+find_minmax(const std::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;
+        }
+    }
+}
+
+std::vector<size_t>
+make_histogram(const std::vector<double>& numbers, size_t bin_count) {
+    std::vector<size_t> bins(bin_count, 0);
+
+    double min, max;
+    find_minmax(numbers, min, max);
+
+    double bin_size = (max - min) / bin_count;
+    if (bin_size == 0) {
+        bin_size = 1;
+    }
+
+    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;
+}

histogram_internal.h

@@ -0,0 +1,8 @@
+#ifndef HISTOGRAM_INTERNAL_H_INCLUDED
+#define HISTOGRAM_INTERNAL_H_INCLUDED
+
+#include <vector>
+
+void find_minmax(const std::vector<double>& numbers, double& min, double& max);
+
+#endif // HISTOGRAM_INTERNAL_H_INCLUDED