сделали bool prompt

main.cpp

@@ -9,21 +9,28 @@ struct Input {
     size_t bin_count{};
 };
 
-Input input_data(std::istream& in) {
+Input input_data(std::istream& in, bool prompt) {
     Input data;
     size_t number_count;
 
+    if(prompt){
     cerr << "Enter the number of elements: ";
-    in >> number_count;
+    }
 
+    in >> number_count;
     data.numbers.resize(number_count);
 
+    if(prompt){
     cerr << "\nEnter " << number_count << " elements:" << endl;
+    }
+
     for (size_t i = 0; i < number_count; i++) {
         in >> data.numbers[i];
     }
-
+    if(prompt){
     cerr << "Enter the number of bins: ";
+    }
+
     in >> data.bin_count;
 
     return data;
@@ -31,7 +38,7 @@ Input input_data(std::istream& in) {
 
 int main() {
     using namespace std;
-    auto in = input_data(cin);
+    auto in = input_data(cin,true);
     auto bins = make_histogram(in.bin_count, in.numbers);
     show_histogram_svg(bins);
     return 0;