код разбит на подпрограммы

main.cpp

@@ -2,23 +2,28 @@
 #include <vector>
 
 using namespace std;
-int main()
-{
+struct Input {
+    vector<double> numbers;
+    size_t bin_count{};
+};
+Input
+input_data(){
     size_t number_count;
-    cerr <<"enter number count: ";
+    cerr << "Number_count: ";
     cin >> number_count;
-
-    vector<double> numbers(number_count);
-    for( int i=0; i<number_count; i++){
-        cerr<<"enter number "<< i+1<<": ";
-        cin>>numbers[i];
+    Input in;
+    in.numbers.resize(number_count);
+    for (size_t i = 0; i < number_count; i++) {
+        cin >> in.numbers[i];
     }
-    size_t bin_count;
-    cerr <<"enter bin count : ";
-    cin >> bin_count;
-    vector<size_t> bins(bin_count);
-    double min=numbers[0];
-    double max=numbers[0];
+    cerr << "Enter bin_count: ";
+    cin >> in.bin_count;
+    return in;
+}
+void
+find_minmax(const vector<double>& numbers, double& min, double& max) {
+    min = numbers[0];
+    max = numbers[0];
     for(double x : numbers){
         if(x<min){
             min=x;
@@ -27,8 +32,14 @@ int main()
             max=x;
         }
     }
+}
+vector<size_t>
+make_histogram(const vector<double>& numbers,size_t bin_count){
+    vector<size_t> bins(bin_count);
+    double min,max;
+    find_minmax(numbers,min,max);
     double bin_size=(max-min)/bin_count;
-    for(size_t i=0; i<number_count; i++){
+    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;
@@ -41,6 +52,10 @@ int main()
             bins[bin_count-1]++;
         }
     }
+    return bins;
+}
+void
+show_histogram(vector<size_t>bins,size_t bin_count){
     size_t Maxbins = 0;
     for (size_t i = 0; i < bin_count; i++)
     {
@@ -88,5 +103,12 @@ int main()
             cout << endl;
         }
     }
+}
+int
+main() {
+    auto in = input_data();
+    auto bins = make_histogram(in.numbers, in.bin_count);
+    show_histogram(bins,in.bin_count);
     return 0;
 }
+