diff --git a/src/analyse/analyse.cc b/src/analyse/analyse.cc
index ca5a6ca..46e4969 100644
--- a/src/analyse/analyse.cc
+++ b/src/analyse/analyse.cc
@@ -1,6 +1,14 @@
-#include <queue>
 #include "analyse.h"
 
+Analyse::Analyse(const RawCode &code) {
+    this->root = (uint64_t)code;
+}
+
+void Analyse::set_root(const RawCode &code) {
+    this->root = (uint64_t)code;
+}
+
+/// memory initialize and return klotski core
 Core Analyse::init(uint64_t code) {
     /// reset working data
     cases.clear();
@@ -41,22 +49,25 @@ void Analyse::new_case(uint64_t code, uint64_t mask) {
     }
 }
 
-void Analyse::build(uint64_t code) {
-    auto core = init(code);
+/// analyse and build klotski tree
+void Analyse::build() {
+    auto core = init(root);
     while (!cache.empty()) {
         core.next_cases(cache.front()->code, cache.front()->mask);
         cache.pop();
     }
 }
 
-std::vector<uint64_t> Analyse::build_until(uint64_t code, const match_t &match) {
-    auto core = init(code);
+std::vector<RawCode> Analyse::build_until(const match_t &match) {
+    auto core = init(root);
     auto layer_end = cache.back();
-    std::vector<uint64_t> matched; // matched list
+    std::vector<RawCode> matched; // matched list
     /// start BFS search
     while (!cache.empty()) {
         if (match(cache.front()->code)) { // match target
-            matched.emplace_back(cache.front()->code);
+            matched.emplace_back(
+                RawCode::unsafe_create(cache.front()->code) // record matched cases
+            );
         }
         core.next_cases(cache.front()->code, cache.front()->mask);
         if (cache.front() == layer_end) { // reach layer ending
@@ -67,5 +78,5 @@ std::vector<uint64_t> Analyse::build_until(uint64_t code, const match_t &match)
         }
         cache.pop();
     }
-    return std::vector<uint64_t>{}; // no target found
+    return std::vector<RawCode>{}; // no target found
 }
diff --git a/src/analyse/analyse.h b/src/analyse/analyse.h
index 2a9f222..474ad52 100644
--- a/src/analyse/analyse.h
+++ b/src/analyse/analyse.h
@@ -6,6 +6,7 @@
 #include <functional>
 #include <unordered_map>
 #include "core.h"
+#include "raw_code.h"
 
 const uint32_t ANY_MAP_RESERVE = 65536;
 
@@ -13,8 +14,13 @@ class Analyse {
 public:
     typedef std::function<bool(uint64_t)> match_t;
 
-    void build(uint64_t code);
-    std::vector<uint64_t> build_until(uint64_t code, const match_t &match);
+    /// setting root code
+    void set_root(const RawCode &code);
+    explicit Analyse(const RawCode &code);
+
+    /// BFS search functions
+    void build();
+    std::vector<RawCode> build_until(const match_t &match);
 
 private:
     struct analyse_t {
diff --git a/src/fast_cal/cal_core.cc b/src/fast_cal/cal_core.cc
index b7cac3c..1480282 100644
--- a/src/fast_cal/cal_core.cc
+++ b/src/fast_cal/cal_core.cc
@@ -88,7 +88,9 @@ std::vector<RawCode> FastCal::target_multi(const match_t &match) {
     /// start BFS search
     while (!cache.empty()) {
         if (match(cache.front()->code)) { // match target
-            matched.emplace_back(cache.front()->code);
+            matched.emplace_back(
+                RawCode::unsafe_create(cache.front()->code) // record matched cases
+            );
         }
         core.next_cases(cache.front()->code, cache.front()->mask);
         if (cache.front() == layer_end) { // reach layer ending
diff --git a/src/fast_cal/fast_cal.h b/src/fast_cal/fast_cal.h
index 32e0664..9b77549 100644
--- a/src/fast_cal/fast_cal.h
+++ b/src/fast_cal/fast_cal.h
@@ -17,7 +17,7 @@ class FastCal {
 public:
     typedef std::function<bool(uint64_t)> match_t;
 
-    /// FastCal start case
+    /// setting root code
     void set_root(const RawCode &code);
     explicit FastCal(const RawCode &code);
 
diff --git a/src/main.cc b/src/main.cc
index 636f6cc..d061092 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -53,8 +53,14 @@ int main() {
 //    }
 
 
-    auto a = Analyse();
-    a.build((uint64_t)RawCode::from_common_code("1a9bf0c"));
+    auto a = Analyse(RawCode::from_common_code("1a9bf0c"));
+//    a.build();
+    auto ret = a.build_until([](uint64_t code) {
+        return ((code >> (3 * 0xD)) & 0b111) == B_2x2;
+    });
+    for (const auto &r : ret) {
+        std::cout << r << std::endl;
+    }
 
 //    auto ret = a.build_until((uint64_t)RawCode::from_common_code("1a9bf0c"), [](uint64_t code) {
 //        return ((code >> (3 * 0xD)) & 0b111) == B_2x2;