diff --git a/src/klotski/all_cases/all_cases.h b/src/klotski/all_cases/all_cases.h
index 8e0fb0d..4eca3c1 100644
--- a/src/klotski/all_cases/all_cases.h
+++ b/src/klotski/all_cases/all_cases.h
@@ -6,7 +6,7 @@
 #include "basic_ranges.h"
 
 namespace klotski {
-    /// all cases count
+    /// all cases count -> memory pre-allocated
     const uint32_t ALL_CASES_SIZE[16] = {
         2942906, 2260392, 2942906, 0,
         2322050, 1876945, 2322050, 0,
diff --git a/src/klotski/all_cases/basic_ranges.h b/src/klotski/all_cases/basic_ranges.h
index 6c03aaf..fc097e8 100644
--- a/src/klotski/all_cases/basic_ranges.h
+++ b/src/klotski/all_cases/basic_ranges.h
@@ -5,7 +5,7 @@
 #include <cstdint>
 
 namespace klotski {
-    /// basic ranges count
+    /// basic ranges count -> memory pre-allocated
     const uint32_t BASIC_RANGES_SIZE = 7311921;
 
     class BasicRanges {
diff --git a/src/klotski/utils/common.h b/src/klotski/utils/common.h
index b103572..fb4ae39 100644
--- a/src/klotski/utils/common.h
+++ b/src/klotski/utils/common.h
@@ -9,9 +9,8 @@
 ///
 ///   3. `2x2` block must have and only one, `2x1` `1x2` `1x1` are not required in number.
 ///
-///  NOTE:  2x2   2x1   1x2   1x1
-///         # #    #    # #    #
-///         # #    #
+///  NOTE:  2x2 -> # #   |   2x1 -> #   |   1x2 -> # #   |   1x1 -> #
+///                # #   |          #   |                |
 ///
 /// After statistics, there are a total of 29334498 cases that meet the above requirements.
 
diff --git a/test/all_cases.cc b/test/all_cases.cc
index 6fa04d6..980822f 100644
--- a/test/all_cases.cc
+++ b/test/all_cases.cc
@@ -3,17 +3,19 @@
 #include "all_cases.h"
 #include "gtest/gtest.h"
 
+using namespace klotski;
+
 /// basic ranges constants
-const uint32_t BASIC_RANGES_SIZE = 7311921;
+//const uint32_t BASIC_RANGES_SIZE = 7311921;
 const char BASIC_RANGES_MD5[] = "6f385dc171e201089ff96bb010b47212";
 
 /// all cases constants
-const uint32_t ALL_CASES_SIZE[16] = {
-    2942906, 2260392, 2942906, 0,
-    2322050, 1876945, 2322050, 0,
-    2322050, 1876945, 2322050, 0,
-    2942906, 2260392, 2942906, 0,
-};
+//const uint32_t ALL_CASES_SIZE[16] = {
+//    2942906, 2260392, 2942906, 0,
+//    2322050, 1876945, 2322050, 0,
+//    2322050, 1876945, 2322050, 0,
+//    2942906, 2260392, 2942906, 0,
+//};
 const uint32_t ALL_CASES_SIZE_SUM = 29334498;
 const char ALL_CASES_MD5[] = "3888e9fab8d3cbb50908b12b147cfb23";