delete tree after simulation is done

lib/nBodySim.cpp

@@ -58,6 +58,7 @@ nBodySim::nBodySim(std::string datafile) {
 }
 
 nBodySim::~nBodySim() {
+    delete tree_;
     delete[] positions_;
     delete[] velocities_;
     delete[] potential_;
@@ -81,7 +82,7 @@ void nBodySim::runSimulation(double dt, unsigned nSteps) {
                                 << ", T = "   << std::setw(8) << duration.count()/1000.0 << " s"
                                 << std::endl;
         updateForces();
-        std::cout << std::right << "correct: " << std::setw(12) << calculateMeanForceMagnitude() << std::endl;
+        std::cout << std::right << "    correct MFM = " << std::setw(12) << calculateMeanForceMagnitude() << std::endl;
         doTimeStep(dt);
         updateTree();
     }