пункт 3: добавила histogram.h

histogram.h

@@ -0,0 +1,8 @@
+#ifndef HISTOGRAM_H_INCLUDED
+#define HISTOGRAM_H_INCLUDED
+#include <vector>
+
+std::vector<size_t>
+make_histogram(const std::vector<double>& numbers, size_t bin_count);
+
+#endif // HISTOGRAM_H_INCLUDED