добавить в input_data новый параметр

main.cpp

@@ -48,10 +48,13 @@ struct Input {
 };
 
 Input
-input_data(istream& in)
+input_data(istream& in, bool promt)
 {
     size_t number_count;
+     if (promt)
+    {
         cerr << "Enter number count: ";
+    }
     in >> number_count;
     Input ik;
     ik.numbers.resize(number_count);
@@ -69,7 +72,7 @@ input_data(istream& in)
 
 int main()
 {
-    auto in = input_data(cin);
+    auto in = input_data(cin, true);
     auto bins = make_histogram(in.numbers, in.bin_count);
     show_histogram_svg(bins);
     getch();