feat: backtrack function for FastCal

src/fast_cal/fast_cal.cc

@@ -31,7 +31,7 @@ void FastCal::new_case(uint64_t code, uint64_t mask) { // callback function for
 
 }
 
-std::vector<uint64_t> FastCal::solve() {
+uint64_t FastCal::solve() {
 
     auto resolved = [](uint64_t code) {
         return ((code >> (3 * 0xD)) & 0b111) == B_2x2;
@@ -40,7 +40,24 @@ std::vector<uint64_t> FastCal::solve() {
 
 }
 
-std::vector<uint64_t> FastCal::target(const std::function<bool(uint64_t)> &match) {
+// TODO: single backtrack function
+std::vector<uint64_t> FastCal::backtrack(uint64_t code) {
+    std::vector<uint64_t> path;
+
+    // TODO: confirm code exist
+    auto node = &cases[code];
+
+    while (node != nullptr) {
+        path.emplace_back(node->code);
+        node = node->last;
+    }
+
+    std::reverse(path.begin(), path.end());
+    return path;
+
+}
+
+uint64_t FastCal::target(const std::function<bool(uint64_t)> &match) {
 
     auto core = import_core();
 
@@ -62,7 +79,6 @@ std::vector<uint64_t> FastCal::target(const std::function<bool(uint64_t)> &match
 
     while (!cache.empty()) {
 
-        /// break check point
         if (match(cache.front()->code)) {
             break;
         }
@@ -73,20 +89,12 @@ std::vector<uint64_t> FastCal::target(const std::function<bool(uint64_t)> &match
 
     std::cout << "size: " << cases.size() << std::endl;
 
-    // TODO: single backtrack function
-
     // TODO: cache may empty -> never found
+    if (!cache.empty()) {
 
-    auto solution = cache.front();
-
-    std::vector<uint64_t> solution_path;
+        return cache.front()->code;
 
-    while (solution != nullptr) {
-        solution_path.emplace_back(solution->code);
-        solution = solution->last;
     }
-
-    std::reverse(solution_path.begin(), solution_path.end());
-    return solution_path;
+    return FastCal::NOT_FOUND;
 
 }

src/fast_cal/fast_cal.h

@@ -20,16 +20,21 @@ public:
     /// xxx_multi only search until same layer
 
 //    std::vector<uint64_t> solve(uint64_t code);
-    std::vector<uint64_t> solve();
+//    std::vector<uint64_t> solve();
+    uint64_t solve();
 //    solve_multi
 
-    std::vector<uint64_t> target(const std::function<bool(uint64_t)> &match);
+//    std::vector<uint64_t> target(const std::function<bool(uint64_t)> &match);
+    uint64_t target(const std::function<bool(uint64_t)> &match);
 
+    std::vector<uint64_t> backtrack(uint64_t code);
 
     // TODO: continue search process? -> reuse exist data (ensure working code not changed)
 
     // TODO: static search functions
 
+    const static auto NOT_FOUND = (uint64_t)0;
+
 private:
     struct fast_cal_t {
         uint64_t code;

src/main.cc

@@ -30,6 +30,7 @@ int main() {
 
     auto f = FastCal(RawCode::from_common_code("1a9bf0c").unwrap());
     auto ret = f.solve();
+    std::cout << RawCode(ret) << std::endl;
 
 //    for (const auto &c : ret) {
 //        std::cout << RawCode(c) << std::endl;