Add test for scan.

test/algorithm_test.cpp

@@ -43,3 +43,21 @@ TEST_CASE("for_each functions correctly", "[algorithms/for_each.h]") {
     }
     }
   });
   });
 }
 }
+
+TEST_CASE("scan functions correctly", "[algorithms/scan.h]") {
+  malloc_scheduler_memory my_scheduler_memory{8, 2 << 12};
+  scheduler my_scheduler{&my_scheduler_memory, 2};
+  my_scheduler.perform_work([]() {
+    constexpr int SIZE = 1000;
+    std::array<int, SIZE> input_array{}, result_array{};
+    input_array.fill(1);
+
+    pls::scan(input_array.begin(), input_array.end(), result_array.begin(), std::plus<int>(), 0);
+
+    bool all_correct = true;
+    for (int i = 0; i < SIZE; i++) {
+      all_correct &= result_array[i] == (i + 1);
+    }
+    REQUIRE (all_correct);
+  });
+}