Code: добавлена возможность выбирать нужно ли выводить в cerr подсказки

main.cpp

@@ -12,17 +12,24 @@ struct Input {
 
 Input
 input_data(istream& stream){
+    bool prompt = true;
     size_t number_count;
-    cerr << "Enter number count:" << endl;
+    if (prompt){
+        cerr << "Enter number count:" << endl;
+    }
     stream >> number_count;
     Input in;
     in.numbers.resize(number_count);
     vector<double> numbers(number_count);
-    cerr << "Enter numbers:" << endl;
+    if (prompt){
+        cerr << "Enter numbers:" << endl;
+    }
     for (size_t i = 0; i < number_count; i++) {
         stream >> in.numbers[i];
     }
-    cerr << "Enter bin count:" << endl;
+    if (prompt){
+        cerr << "Enter bin count:" << endl;
+    }
     stream >> in.bin_count;
     return in;
 }