little cleaning of the solution

exercises/week3/stl/solution/CMakeLists.txt

 cmake_minimum_required(VERSION 2.6)
+project(stl-exercise)
 
 add_executable(stl
   main.cc

exercises/week3/stl/solution/main.cc

@@ -114,11 +114,10 @@ int main(int argc, char ** argv){
   //Triplet origin_coordinates(0.,0.,0.);
   map["sun"] = origin_coordinates;
 
-  std::map<std::string,Triplet>::iterator end3 = map.end();
+  auto end3 = map.end();
 
-  //origin_coordinates.coords[0] = 1.;
   origin_coordinates[0] = 1.;
-  std::map<std::string,Triplet>::iterator it3 = map.find("earth");
+  auto it3 = map.find("earth");
   if (it3 == end3) map["earth"] = origin_coordinates;
 
   std::set<std::string> keys;