1 files changed, 34 insertions, 1 deletions
diff --git a/src/2017/day21/aoc.cpp b/src/2017/day21/aoc.cpp
index 706fa8a..716d4e6 100644
--- a/src/2017/day21/aoc.cpp
+++ b/src/2017/day21/aoc.cpp
@@ -1,6 +1,39 @@
 #include "aoc.h"
+#include <map>
 
 namespace aoc2017 {
 
-std::pair<int64_t, int64_t> day21(line_view) { return {0, 0}; }
+std::pair<int64_t, int64_t> day21(line_view file) {
+  std::map<std::string, std::string> rules;
+
+  per_line(file, [&rules](line_view lv) {
+    const char* p0 = lv.line;
+    const char* p1 = p0;
+    std::string k;
+    std::string v;
+    while (p1 < lv.line + lv.length) {
+      if (*p1 == '=') {
+        k = std::string{p0, (size_t)(p1 - p0 - 1)};
+        p0 = p1 + 3;
+      }
+      if (*p1 == '\n') {
+        v = std::string{p0, (size_t)(p1 - p0)};
+      }
+      p1++;
+    }
+    rules.insert({k, v});
+    return true;
+  });
+
+  // .#.
+  // ..#
+  // ###
+  square3 s3{".#./..#/###"};
+
+  // for (auto& kv : rules) {
+  //   printf("%s => %s\n", kv.first.c_str(), kv.second.c_str());
+  // }
+
+  return {0, 0};
+}
 } // namespace aoc2017