Comment out some Kokkos call in Begin exercises

advanced_reductions.cpp and parallel_scan.cpp cannot compile due to missing code (the exercise).

Author: cedricchevalier19

Exercises/advanced_reductions/Begin/advanced_reductions.cpp

@@ -40,7 +40,8 @@ int main(int argc, char *argv[]) {
         n, KOKKOS_LAMBDA(int i) { view(i) = 1 + i / 10.; });
 
     double result;
-    Kokkos::parallel_reduce(n, GeometricMean{view}, result);
+    // EXERCISE uncomment the following line when GeometricMean is implemented
+    // Kokkos::parallel_reduce(n, GeometricMean{view}, result);
 
     auto host_view =
         Kokkos::create_mirror_view_and_copy(Kokkos::HostSpace{}, view);

Exercises/parallel_scan/Begin/parallel_scan.cpp

@@ -27,7 +27,8 @@ int main(int argc, char *argv[]) {
     int n = 10;
     Kokkos::View<double *> view("view", n);
 
-    Kokkos::parallel_scan(n, Factorial{view});
+    // EXERCISE Uncomment when Factorial is implemented
+    // Kokkos::parallel_scan(n, Factorial{view});
 
     auto host_view =
         Kokkos::create_mirror_view_and_copy(Kokkos::HostSpace{}, view);