rt/examples: Improve shuffle examples

rt/examples/shuffle_baseline.cpp

@@ -7,7 +7,21 @@
 
 using u32 = std::uint_fast32_t;
 
-u32 N = u32(1) << 26;
+u32 N = u32(1) << 28;
+long C = N >> 10;
+
+template <typename RandomIt>
+void sequential_shuffle(RandomIt first, RandomIt last)
+{
+  auto it = first;
+  for (; it < last; it += C) {
+    std::shuffle(it, it + C, std::mt19937{std::random_device{}()});
+  }
+  if (it < last)
+  {
+    std::shuffle(it, last, std::mt19937{std::random_device{}()});
+  }
+}
 
 int main() {
   std::vector<u32> v;
@@ -15,7 +29,7 @@ int main() {
   for (u32 i = 0; i < N; i++) {
     v.push_back(i);
   }
-  std::shuffle(v.begin(), v.end(), std::mt19937{std::random_device{}()});
+  sequential_shuffle(v.begin(), v.end());
   printf("v[0] = %lu\n", v[0]);
   puts("done");
 }

rt/examples/shuffle_fork.cpp

@@ -8,8 +8,8 @@
 
 using namespace typon;
 
-long N = 1 << 26;
-long C = N >> 8;
+long N = 1 << 28;
+long C = N >> 10;
 
 template <typename RandomIt>
 Task<void> shuffle(RandomIt first, RandomIt last)