scale implement

main.cpp

@@ -20,20 +20,22 @@ int prompti(string,bool*);
 double promptd(string,bool*);
 double avgitr(std::list<double>*);
 double avgfor(std::list<double>*);
+void scale(std::list<double>&,double);
 
 
 int main() {
-  printlm("Average of:");
+  printlm("Scale:");
   bool s {};
   std::list<double> lst {};
   do {
     auto v = promptd("Enter a double value: ", &s);
     if (s) lst.push_back(v);
   } while (s);
-  printm("avgitr: ");
-  printlm(avgitr(&lst));
-  printm("avgfor: ");
-  printlm(avgfor(&lst));
+  auto scalef = promptd("Enter double scalar: ", &s);
+  if (!s) return -1;
+  printlm("Scaled:");
+  scale(lst, scalef);
+  for (const auto c : lst) printlm(c);
   return 0;
 }
 
@@ -71,6 +73,10 @@ double avgitr(std::list<double> *values) {
 
 double avgfor(std::list<double> *values) {
   double sum {};
-  for (auto c : *values) sum += c;
+  for (const auto c : *values) sum += c;
   return sum / values->size();
 }
+
+void scale(std::list<double> &values, double sf) {
+  for (auto &c : values) c *= sf;
+}