From a7c0779f5adad7e3cf8d4d7a8a0ab64e98243bb6 Mon Sep 17 00:00:00 2001
From: Dnomd343 <i@343.re>
Date: Fri, 6 Jan 2023 11:24:43 +0800
Subject: [PATCH] feat: tiny encode function for short code

---
 klotski/main.cc       |  1 +
 klotski/short_code.cc | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/klotski/main.cc b/klotski/main.cc
index e243018..1ced2bb 100644
--- a/klotski/main.cc
+++ b/klotski/main.cc
@@ -34,6 +34,7 @@ int main() {
     auto s = ShortCode();
     s.speed_up(ShortCode::Mode::NORMAL); // enter normal mode first
 
+    printf("%d\n", s.tiny_encode(0x6EC0F8800));
     printf("%09lX\n", s.tiny_decode(14323231));
 
     return 0;
diff --git a/klotski/short_code.cc b/klotski/short_code.cc
index edb61c3..38985ba 100644
--- a/klotski/short_code.cc
+++ b/klotski/short_code.cc
@@ -79,3 +79,23 @@ uint64_t ShortCode::tiny_decode(uint32_t short_code) { // short_code --low-mem--
     }
     return (uint64_t)head << 32 | Common::range_reverse(range); // release common code
 }
+
+// TODO: ensure input common_code valid
+// TODO: load basic ranges before tiny_encode
+uint32_t ShortCode::tiny_encode(uint64_t common_code) {
+    uint32_t offset = 0;
+    uint32_t head = common_code >> 32; // common code head
+    uint32_t prefix = (common_code >> 24) & 0xFF; // common code range prefix
+    auto target = Common::range_reverse((uint32_t)common_code); // target range
+
+    for (int index = 0; index < BASIC_RANGES_INDEX[prefix]; ++index) { // traverse basic ranges
+        uint32_t range = basic_ranges[index + BASIC_RANGES_OFFSET[prefix]];
+        if (range == target) {
+            break; // found target range
+        }
+        if (Common::check_case(head, range)) { // search for valid cases
+            ++offset; // record sub offset
+        }
+    }
+    return ALL_CASES_OFFSET[head] + RANGE_PREFIX_OFFSET[head][prefix] + offset;
+}