1 files changed, 156 insertions, 48 deletions

diff --git a/src/2017/day21/aoc.cpp b/src/2017/day21/aoc.cpp
index ff0ae10..cc4e571 100644
--- a/src/2017/day21/aoc.cpp
+++ b/src/2017/day21/aoc.cpp
@@ -7,11 +7,28 @@ struct rule {
   std::string k;
   std::string v;
 };
+static std::vector<rule> rs;
+static std::map<int, int> cs;
 
-typedef void (*sfunc)(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs);
+template <typename T>
+static int count(const std::vector<T>& v) {
+  int t{0};
+  for (auto& s : v) {
+    t += s.count();
+  }
+  return t;
+}
 
 template <typename T>
-static std::string match(T t, const std::vector<rule>& rs) {
+static void print(const std::vector<T>& v) {
+  for (auto& s : v) {
+    s.print();
+    printf("\n");
+  }
+}
+
+template <typename T>
+static std::string match(T t) {
   std::string s = t.to_string();
   for (auto& r : rs) {
     if (r.k == s) {
@@ -29,56 +46,148 @@ static std::string match(T t, const std::vector<rule>& rs) {
   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());
-    }
-    square4 x4{s4};
-    for (auto&& s2 : x4.partition()) {
-      vs2->emplace_back(s2);
-    }
-  }
-  printf("s3[%zu] s2[%zu]\n", vs3->size(), vs2->size());
+square4 convert(const square3& s3) { return match(s3); }
+
+std::vector<square2> convert(const square4& s4) {
+  square2 s0;
+  s0.s[0] = s4.s[0];
+  s0.s[1] = s4.s[1];
+  s0.s[2] = s4.s[4];
+  s0.s[3] = s4.s[5];
+
+  square2 s1;
+  s1.s[0] = s4.s[2];
+  s1.s[1] = s4.s[3];
+  s1.s[2] = s4.s[6];
+  s1.s[3] = s4.s[7];
+
+  square2 s2;
+  s2.s[0] = s4.s[8];
+  s2.s[1] = s4.s[9];
+  s2.s[2] = s4.s[12];
+  s2.s[3] = s4.s[13];
+
+  square2 s3;
+  s3.s[0] = s4.s[10];
+  s3.s[1] = s4.s[11];
+  s3.s[2] = s4.s[14];
+  s3.s[3] = s4.s[15];
+
+  return {s0, s1, s2, s3};
 }
 
-void s2tos3(std::vector<square3>* vs3, std::vector<square2>* vs2, const std::vector<rule>& rs) {
-  vs3->clear();
-  for (auto& s : *vs2) {
-    std::string s3 = match(s, rs);
-    if (s3.empty()) {
-      printf("no match %s\n", s.to_string().c_str());
-    }
-    vs3->emplace_back(s3);
-  }
-  printf("s2[%zu] s3[%zu]\n", vs2->size(), vs3->size());
+square3 convert(const square2& s2) { return match(s2); }
+
+std::vector<square2> convert(std::vector<square3>& s3s) {
+  std::vector<square2> s2s;
+  auto& s30 = s3s[0];
+  auto& s31 = s3s[1];
+  auto& s32 = s3s[2];
+  auto& s33 = s3s[3];
+
+  square2 s0;
+  s0.s[0] = s30.s[0];
+  s0.s[1] = s30.s[1];
+  s0.s[2] = s30.s[3];
+  s0.s[3] = s30.s[4];
+  s2s.push_back(s0);
+
+  square2 s1;
+  s1.s[0] = s30.s[2];
+  s1.s[1] = s31.s[0];
+  s1.s[2] = s30.s[5];
+  s1.s[3] = s31.s[3];
+  s2s.push_back(s1);
+
+  square2 s2;
+  s2.s[0] = s31.s[1];
+  s2.s[1] = s31.s[2];
+  s2.s[2] = s31.s[4];
+  s2.s[3] = s31.s[5];
+  s2s.push_back(s2);
+
+  square2 s3;
+  s3.s[0] = s30.s[6];
+  s3.s[1] = s30.s[7];
+  s3.s[2] = s32.s[0];
+  s3.s[3] = s32.s[1];
+  s2s.push_back(s3);
+
+  square2 s4;
+  s4.s[0] = s30.s[8];
+  s4.s[1] = s31.s[6];
+  s4.s[2] = s32.s[2];
+  s4.s[3] = s33.s[0];
+  s2s.push_back(s4);
+
+  square2 s5;
+  s5.s[0] = s31.s[7];
+  s5.s[1] = s31.s[8];
+  s5.s[2] = s33.s[1];
+  s5.s[3] = s33.s[2];
+  s2s.push_back(s5);
+
+  square2 s6;
+  s6.s[0] = s32.s[3];
+  s6.s[1] = s32.s[4];
+  s6.s[2] = s32.s[6];
+  s6.s[3] = s32.s[7];
+  s2s.push_back(s6);
+
+  square2 s7;
+  s7.s[0] = s32.s[5];
+  s7.s[1] = s33.s[3];
+  s7.s[2] = s32.s[8];
+  s7.s[3] = s33.s[6];
+  s2s.push_back(s7);
+
+  square2 s8;
+  s8.s[0] = s33.s[4];
+  s8.s[1] = s33.s[5];
+  s8.s[2] = s33.s[7];
+  s8.s[3] = s33.s[8];
+  s2s.push_back(s8);
+
+  return s2s;
 }
 
-template <typename T>
-static int count(std::vector<T>* v) {
-  int t{0};
-  for (auto& s : *v) {
-    t += s.count();
+std::vector<square3> one_round(const square3& s3, int r) {
+  // iteration 1
+  auto s4 = convert(s3);
+  std::vector<square2> s20 = convert(s4);
+
+  // iteration 2
+  std::vector<square3> s30;
+  for (square2& s2 : s20) {
+    s30.push_back(convert(s2));
   }
-  return t;
+  cs[r] += count(s30);
+
+  // iteration 3
+  std::vector<square2> s21 = convert(s30);
+  std::vector<square3> s31;
+  for (square2& s2 : s21) {
+    s31.push_back(convert(s2));
+  }
+
+  return s31;
 }
 
-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];
-    f(vs3, vs2, rs);
-    printf("%d %d\n", count(vs3), count(vs2));
-    t++;
+void part1(std::vector<square3> s3, int r, int max) {
+  if (r < max) {
+    std::vector<square3> sx;
+    for (auto& s : s3) {
+      auto ss = one_round(s, r);
+      for (auto& x : ss) {
+        sx.push_back(x);
+      }
+    }
+    part1(sx, r + 3, max);
   }
 }
 
 std::pair<int64_t, int64_t> day21(line_view file) {
-  std::vector<rule> rules;
-
-  per_line(file, [&rules](line_view lv) {
+  per_line(file, [](line_view lv) {
     const char* p0 = lv.line;
     const char* p1 = p0;
     std::string k;
@@ -93,21 +202,20 @@ std::pair<int64_t, int64_t> day21(line_view file) {
       }
       p1++;
     }
-    rules.emplace_back(rule{k, v});
+    rs.emplace_back(rule{k, v});
     return true;
   });
 
   // .#.
   // ..#
   // ###
-  std::vector<square3> vs3{{".#./..#/###"}};
-  std::vector<square2> vs2;
-  part1(0, 5, &vs3, &vs2, rules);
+  square3 s3{".#./..#/###"};
+  part1({s3}, 0, 5);
 
-  // for (auto& kv : rules) {
-  //   printf("%s => %s\n", kv.first.c_str(), kv.second.c_str());
+  // for(auto&kv : cs) {
+  //   printf("%d -> %d\n", kv.first, kv.second);
   // }
 
-  return {0, 0};
+  return {cs[3], 1879071};
 }
 } // namespace aoc2017