2 files changed, 64 insertions, 37 deletions

diff --git a/src/2017/day21/aoc.cpp b/src/2017/day21/aoc.cpp
index f3047e7..876f1a0 100644
--- a/src/2017/day21/aoc.cpp
+++ b/src/2017/day21/aoc.cpp
@@ -3,22 +3,35 @@
 
 namespace aoc2017 {
 
-typedef void (*sfunc)(std::vector<square3>* vs3, std::vector<square2>* vs2,
-                      const std::map<std::string, std::string>& rs);
+struct rule {
+  std::string k;
+  std::string v;
+};
 
-void s3tos2(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::map<std::string, std::string>& rs) {
-  vs2->clear();
-  for (auto& s : *vs3) {
-    std::string s4;
-    auto vs = s.combo();
-    for (auto& c : vs) {
-      std::string x = c.to_string();
-      auto it = rs.find(x);
-      if (it != rs.end()) {
-        s4 = it->second;
-        break;
+typedef void (*sfunc)(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs);
+
+template <typename T>
+static std::string match(T t, const std::vector<rule>& rs) {
+  std::string s = t.to_string();
+  for (auto& r : rs) {
+    if (r.k == s) {
+      return r.v;
+    }
+  }
+  for (auto& r : rs) {
+    for (auto&& sx : t.combo()) {
+      if (sx.to_string() == r.k) {
+        return r.v;
       }
     }
+  }
+  return "";
+}
+
+void s3tos2(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs) {
+  vs2->clear();
+  for (auto& s : *vs3) {
+    std::string s4 = match(s, rs);
     if (s4.empty()) {
       printf("no match %s\n", s.to_string().c_str());
     }
@@ -30,19 +43,10 @@ void s3tos2(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::map
   printf("s3[%zu] s2[%zu]\n", vs3->size(), vs2->size());
 }
 
-void s2tos3(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::map<std::string, std::string>& rs) {
+void s2tos3(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs) {
   vs3->clear();
   for (auto& s : *vs2) {
-    std::string s3;
-    auto vs = s.combo();
-    for (auto& c : vs) {
-      std::string x = c.to_string();
-      auto it = rs.find(x);
-      if (it != rs.end()) {
-        s3 = it->second;
-        break;
-      }
-    }
+    std::string s3 = match(s, rs);
     if (s3.empty()) {
       printf("no match %s\n", s.to_string().c_str());
     }
@@ -60,8 +64,7 @@ static int count(std::vector<T>* v) {
   return t;
 }
 
-static void part1(int t, int times, std::vector<square3>* vs3, std::vector<square2>* vs2,
-                  const std::map<std::string, std::string>& rs) {
+static void part1(int t, int times, std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs) {
   sfunc fs[2] = {s3tos2, s2tos3};
   while (t < times) {
     sfunc f = fs[t % 2];
@@ -72,7 +75,7 @@ static void part1(int t, int times, std::vector<square3>* vs3, std::vector<squar
 }
 
 std::pair<int64_t, int64_t> day21(line_view file) {
-  std::map<std::string, std::string> rules;
+  std::vector<rule> rules;
 
   per_line(file, [&rules](line_view lv) {
     const char* p0 = lv.line;
@@ -89,7 +92,7 @@ std::pair<int64_t, int64_t> day21(line_view file) {
       }
       p1++;
     }
-    rules.insert({k, v});
+    rules.emplace_back(rule{k, v});
     return true;
   });
 
@@ -98,7 +101,7 @@ std::pair<int64_t, int64_t> day21(line_view file) {
   // ###
   std::vector<square3> vs3{{".#./..#/###"}};
   std::vector<square2> vs2;
-  part1(0, 6, &vs3, &vs2, rules);
+  part1(0, 5, &vs3, &vs2, rules);
 
   // for (auto& kv : rules) {
   //   printf("%s => %s\n", kv.first.c_str(), kv.second.c_str());
diff --git a/src/2017/day21/aoc.h b/src/2017/day21/aoc.h
index 4b2c464..1f743c2 100644
--- a/src/2017/day21/aoc.h
+++ b/src/2017/day21/aoc.h
@@ -20,11 +20,18 @@ struct square2 {
 
   std::vector<square2> flip() const noexcept {
     square2 s0;
-    for (int i = 0; i < 4; i++) {
-      s0.s[i] = s[i] == '#' ? '.' : '#';
-    }
+    s0.s[0] = s[1];
+    s0.s[1] = s[0];
+    s0.s[2] = s[3];
+    s0.s[3] = s[2];
+
+    square2 s1;
+    s1.s[0] = s[2];
+    s1.s[1] = s[3];
+    s1.s[2] = s[0];
+    s1.s[3] = s[1];
 
-    return {s0};
+    return {s0, s1};
   }
 
   std::vector<square2> rotate() const noexcept {
@@ -99,11 +106,28 @@ struct square3 {
 
   std::vector<square3> flip() const noexcept {
     square3 s0;
-    for (int i = 0; i < 9; i++) {
-      s0.s[i] = s[i] == '#' ? '.' : '#';
-    }
+    s0.s[0] = s[2];
+    s0.s[1] = s[1];
+    s0.s[2] = s[0];
+    s0.s[3] = s[5];
+    s0.s[4] = s[4];
+    s0.s[5] = s[3];
+    s0.s[6] = s[8];
+    s0.s[7] = s[7];
+    s0.s[8] = s[6];
+
+    square3 s1;
+    s1.s[0] = s[6];
+    s1.s[6] = s[0];
+    s1.s[3] = s[3];
+    s1.s[1] = s[7];
+    s1.s[7] = s[1];
+    s1.s[4] = s[4];
+    s1.s[2] = s[8];
+    s1.s[8] = s[2];
+    s1.s[5] = s[5];
 
-    return {s0};
+    return {s0, s1};
   }
 
   std::vector<square3> rotate() const noexcept {