small improvement from workshop dry run

examples/HelloArgon.cpp

@@ -38,7 +38,7 @@ void simulateArgon()
     std::vector<OpenMM::Vec3> initPosInNm(3);
     for (int a = 0; a < 3; ++a) 
     {
-        initPosInNm[a] = OpenMM::Vec3(a/2.,0,0); // location, nm
+        initPosInNm[a] = OpenMM::Vec3(0.5*a,0,0); // location, nm
 
         system.addParticle(39.95); // mass of Ar, grams per mole
 

examples/HelloArgonInC.c

@@ -41,7 +41,7 @@ void simulateArgon()
     initPosInNm = OpenMM_Vec3Array_create(3);
     for (a = 0; a < 3; ++a) 
     {
-        const double posNm[3] = {a/2., 0, 0};     /*location, nm*/
+        const double posNm[3] = {0.5*a, 0, 0};     /*location, nm*/
         OpenMM_Vec3Array_set(initPosInNm, a, posNm);
 
         OpenMM_System_addParticle(system, 39.95); /*mass of Ar, grams/mole*/